Alexa.com is a great site for figuring out (roughly) how popular a website is. It's not perfect, especially on sites that don't get a lot of traffic. But as sites get more popular, it does tend to show a good relative ranking.

. .

WinCustomize.com is one of the sites I administer on. It gets nearly 2 million unique visitors per month.  Oddly, in the last couple of months it's relative ranking has been dropping (i.e. bad). This has been strange because the sites's raw traffic has increased substantially. Which would imply either that the top sites are getting more popular faster or there's some sort of flaw in the Alexa system that is not showing up.

I do tend to take Alexa's numbers with a grain of salt. For some reason, many foreign sites some how have ridiculously high numbers:

Here is the top 100:

1.	Yahoo! Inc. Provides intuitive, context-based guides to online content, Web search capabilities, third-party content and community and personalization features which enable Web users to locate and access desired information and services. (Nasdaq: YHOO). www.yahoo.com - Site info
2.	Microsoft Network Dialup access & content provider www.msn.com - Site info
3.	다음daum No. 1 우리 인터넷. 무료 이메일 서비스, 온라인 쇼핑, 동호회 서비스 www.daum.net - Site info
4.	네이버 통합 검색과 디렉토리, 웹페이지, 해외사이트, 멀티미디어, 뉴스 검색을 지원하는 검색 포털. www.naver.com - Site info
5.	Google Enables users to search the Web, Usenet, and images. Features include PageRank, caching and translation of results, and an option to find similar pages. The company's focus is developing search technology. www.google.com - Site info
6.	Yahoo! JAPAN 掲示板、オークションなどの参加型コンテンツがあるディレクトリ。 www.yahoo.co.jp - Site info
7.	Passport.net www.passport.net - Site info
8.	Microsoft Corporation Designs, develops, manufactures, licenses, sells and supports a wide range of software products. (Nasdaq: MSFT). www.microsoft.com - Site info
9.	E-Bay Consumer to Consumer Auctions www.ebay.com - Site info
10.	Sayclub.com www.sayclub.com - Site info
11.	Bugsmusic.co.kr www.bugsmusic.co.kr - Site info
12.	新浪网 提供新闻、经济和生活资讯，网站目录及电邮。 www.sina.com.cn - Site info
13.	넷마블 즐거운 게임세상 배틀가로세로 퀴즈마블 워드크래프트 워드워 워드빙고 최강헥사 최강테트리스 파워 알까기(장기) 파워 알까기(바둑) 바 둑 장 기 오 목 따 목 상 목 고스톱 섯 다 세븐포커 슬롯머신 www.netmarble.net - Site info
14.	Amazon.com, Inc. Retails books, as well as limited selection of cds, videotapes, audiotapes and other products, on its online retrieval service through the company's web site. (Nasdaq: AMZN) www.amazon.com - Site info
15.	Go A searchable directory, news, stocks, sports and free e-mail. www.go.com - Site info
16.	Sohu.com Inc. Produces Chinese language Internet portal and internet communities. (Nasdaq: SOHU). www.sohu.com - Site info
17.	网易 提供虚拟社区和电邮服务。 www.163.com - Site info
18.	Nate SKT의 유·무선 종합 포털 www.nate.com - Site info
19.	AOL Anywhere America Online's official site. www.aol.com - Site info
20.	CNN Interactive News, weather, sports, and services including e-mail news alerts and downloadable audio/video reports. www.cnn.com - Site info
21.	TOM.COM 提供新闻、生活资讯、电邮、聊天及短信服务等。 www.tom.com - Site info
22.	3721网络实名 提供中文网址软件服务、网络实名介绍和相关服务。 www.3721.com - Site info
23.	Gator Fills out online forms and remembers passwords. Free. www.gator.com - Site info
24.	프리챌 현실사회의 공동체를 사이버에서 더욱 발전시켜 갈 수 있도록 하는 커뮤니티 전문 인터넷 서비스 www.freechal.com - Site info
25.	BBC Online British Public Broadcasting for the United Kingdom. www.bbc.co.uk - Site info
26.	한미르 웹검색, 전화번호 검색이 동시에 한미르 www.hanmir.com - Site info
27.	MSNBC Provides up-to-date news and weather information from around the country. www.msnbc.com - Site info
28.	드림위즈 인터넷 포탈서비스 이메일,무료홈페이지,검색,클럽 ... www.dreamwiz.com - Site info
29.	다모임넷 옛날 짝꿍,지금 짝꿍,모두 모여 떠드는 곳. 학교찾기, 동호회, 프로필 만들기, 경매, 아르바이트 구인광고, 게임 등등. www.damoim.net - Site info
30.	Msn.co.jp www.msn.co.jp - Site info
31.	옥션 auction, 인터넷경매,경매 사이트 옥션 www.auction.co.kr - Site info
32.	Bugs.co.kr www.bugs.co.kr - Site info
33.	Hotmail.com www.hotmail.com - Site info
34.	엠파스 자연어 검색엔진. 사운드 및 mp3, 이미지, 동영상, 업무문서, 압축파일 검색 제공. www.empas.com - Site info
35.	Cliks.org www.cliks.org - Site info
36.	Infoseek Japan 日本語版インフォシーク。ロボット型サーチエンジンと、特選サイトのディレクトリ。 www.infoseek.co.jp - Site info
37.	조선일보 디지틀 조선일보 (Digital Chosunilbo) www.chosun.com - Site info
38.	Searchscout.com www.searchscout.com - Site info
39.	Premium-offers.com www.premium-offers.com - Site info
40.	Google.co.jp www.google.co.jp - Site info
41.	楽天市場 各種の通販サイトをバーチャル店舗として入居させているショッピングモール。オークションや共同購入も開催。 www.rakuten.co.jp - Site info
42.	Overture Services, Inc. Provides web directories, internet search and information services. (Formerly known as GoTo.com, Inc.) (Nasdaq: OVER). www.overture.com - Site info
43.	HiNet 台灣的網際網路服務公司。 www.hinet.net - Site info
44.	Comcast.net www.comcast.net - Site info
45.	百度搜索引擎 提供智能型中文搜索引擎。 www.baidu.com - Site info
46.	Com.com www.com.com - Site info
47.	Lycos, Inc. Develops and provides guides to find, index and filter information on the internet and the world wide web. (Nasdaq: LCOS). www.lycos.com - Site info
48.	KBS KBS, 한국방송공사, 프로그램 정보, 뉴스, kbs news. www.kbs.co.kr - Site info
49.	TrafficSyndicate Generate revenue from your website traffic with TrafficSyndicate. www.trafficsyndicate.com - Site info
50.	Kbstar.com www.kbstar.com - Site info
51.	Match.com Personal ads with photos, anonymous email, advice and date ideas. www.match.com - Site info
52.	The Weather Channel Site offers forecasts for over 1600 cities worldwide as well as numerous radar and satellite maps. Also includes the latest weather news stories and allergy information. www.weather.com - Site info
53.	Trafficmp.com www.trafficmp.com - Site info
54.	Mapquest Provides online maps, driving directions and trip planning. The toolbar provides the map functionality in your browser. www.mapquest.com - Site info
55.	Netscape Composer Additional component of Communicator suite (includes Navigator). www.netscape.com - Site info
56.	EBay UK Person-to-person trading site with over 4,000 categories. www.ebay.co.uk - Site info
57.	ジオシティーズ ジャパン 容量12MBの無料ウェブスペース。各種ツール(カウンター、ゲストブック等)の使用が可能。 www.geocities.co.jp - Site info
58.	MSN 마이크로소프트 네트웍 www.msn.co.kr - Site info
59.	Hanafos.com www.hanafos.com - Site info
60.	PC home 電腦報 網路家庭 [Taiwan] www.pchome.com.tw - Site info
61.	New York Times Online Official site and online edition of this famous New York publication. Free registration required. www.nytimes.com - Site info
62.	스포츠서울 대한매일·스포츠서울 뉴스넷(Korea Newsnet) www.sportsseoul.com - Site info
63.	DoubleClick Inc. Provides comprehensive Internet advertising solutions, including fully-outsourced ad sales, delivery and related services, and technology that provides the ability to control the targeting, delivery, measurement and analysis of online marketing campaigns, to advertisers and web publishers worldwide. (Nasdaq: DCLK). www.doubleclick.net - Site info
64.	AltaVista This search engine also offers a directory provided by the Open Directory. www.altavista.com - Site info
65.	Webshots Download free screen saver, wallpaper, and photos. www.webshots.com - Site info
66.	MGame 위즈게이트 게임의 통합 사이트 .'넷바둑', '넷장기', '넷오목', '넷체스', '넷테트리스', '넷고도리' www.mgame.com - Site info
67.	Google UK The local version of this pre-eminent search engine, offering UK-specific pages as well as world results. www.google.co.uk - Site info
68.	DoubleClick Inc. Provides comprehensive Internet advertising solutions, including fully-outsourced ad sales, delivery and related services, and technology that provides the ability to control the targeting, delivery, measurement and analysis of online marketing campaigns, to advertisers and web publishers worldwide. (Nasdaq: DCLK). www.doubleclick.com - Site info
69.	Universo Online O Universo Online é um grande provedor de acesso e de conteúdo em língua portuguesa. Salas de bate papo, noticias e suporte ao usuário. www.uol.com.br - Site info
70.	IMBC 인터넷 MBC www.imbc.com - Site info
71.	Google.ca www.google.ca - Site info
72.	Pogo.com Provider of family-based games for everyone including card, board, word, trivia, bingo and casino games with no software installation, plug-ins or long download time. www.pogo.com - Site info
73.	Excite.com www.excite.com - Site info
74.	중앙일보 중앙일보 (JoongAng Ilbo) www.joins.com - Site info
75.	Kinghost.com www.kinghost.com - Site info
76.	Maxmp3.co.kr MP3자료 | 음악감상.음악편지 | MP3순위 | 곡평가하기 | 가사자료 | 사진자료 | 프리보드&클럽 | www.maxmp3.co.kr - Site info
77.	디어유컴 사랑, 안부, 우정, 유머, 생일, 결혼/축하 카드 등 다양한 종류의 카테고리 www.dearyou.com - Site info
78.	Goodday 좋은신문 좋은하루 www.hot.co.kr - Site info
79.	IG - Internet Grátis Correio bastante vulnerável a Spam, acesso de qualidade mediana. www.ig.com.br - Site info
80.	WindowsMedia.com A portal for online streaming media using the Windows Media format. Includes music videos, radio stations, and news headlines. www.windowsmedia.com - Site info
81.	Monster.com A one-stop career management resource. Job search, resume management, 1200 pages of advice from career experts, plus chats and message boards on dozens of topics. www.monster.com - Site info
82.	Revenue.net www.revenue.net - Site info
83.	Goo.ne.jp www.goo.ne.jp - Site info
84.	Dell Computer Corporation Designs, develops, manufactures, markets, services and supporst high-performance computer systems and related equipment, including workstations, desktop systems, notebooks and network servers, as well as software, peripherals and service and support programs. (Nasdaq: DELL). www.dell.com - Site info
85.	Internet Fuel Internet marketing agency using Exit Direct and Exit Fuel marketing tools. www.internetfuel.com - Site info
86.	About.com, Inc. Web portal and directory providing Internet news, information and entertainment service which focuses on particular topic and is managed by a human guide. (Nasdaq: BOUT). www.about.com - Site info
87.	Chol.com www.chol.com - Site info
88.	Nastydollars.com www.nastydollars.com - Site info
89.	Cgiworld.net www.cgiworld.net - Site info
90.	The Internet Movie Database Features plot summaries, reviews, cast lists, and theatre schedules. www.imdb.com - Site info
91.	Exitfuel.com Affiliate programs for webmasters' exit traffic. www.exitfuel.com - Site info
92.	Fastclick An advertising network designed to provide clients with the most advanced technology available to ensure successful campaigns with real-time results. www.fastclick.com - Site info
93.	Adult Friendfinder Adult personal ads with pictures and chat. [Membership] www.adultfriendfinder.com - Site info
94.	모교사랑 학교별 동문커뮤니티를 운영하며 선배들이 방문할 때마다 누적되는 포인트를 현금화해 모교에게 장학금으로 지급. 친구찾기, 계시판, 아바타, 게임, 대화방, 쇼핑 등등. www.iloveschool.co.kr - Site info
95.	Tripod 50 Mb. Provides tools to help beginners learn HTML. www.tripod.com - Site info
96.	21CN 免费电子信箱，并提供新闻报道，短信服务和不同方面的专栏。 www.21cn.com - Site info
97.	Yam.com www.yam.com - Site info
98.	IWon Portal and search engine that gives away cash prizes daily, monthly, and yearly. www.iwon.com - Site info
99.	EzBoard Designed to be a seamless addition to a website. Free. www.ezboard.com - Site info
100.	Com.ne.kr www.com.ne.kr - Site info

 

Sorry but some site called Naver.com is not more popular than Google. I am almost convinced that some of these foreign language sites mess around with the Alexa system to manipulate their rank. I wish Alexa took a more active roll in trying to resolve that. I'd be interested in knowing our site's ranking in the English speaking world anyway since we're not going to be competing with Korea any time soon for visitors.