I’ll start it off, with some of my favorites, many of which I found out about here on the SDMB.
Great sound files / songs. Hilarious stuff:
http://www.earthstation1.com/aUdIo_WeIrDnEsS.html
Bob Rivers, parody songer extraordinarre:
Great U2 site:
http://atu2.com/
Great place to find used music or movies:
Quicktime movie trailers:
http://www.movie-list.com/comingsoon.shtml
Star Wars Bloopers:
http://www.night-flight.com/bloopers.html
I’d love to see some more cool stuff.
one i visit every day:
http://www.lileks.com
Columnist for a Minnesota newspaper. Writes about his life in a daily diary, but has sections where he riffs on “found art.” He’s currently dissing '70s design books, foreign money, and really obscure newspaper comics. He also is fascinated with architecture and is cataloging various streets in Minneapolis/St. Paul with before and after pictures.
Oh, and Art Frahm, the world’s weirdest pin-up artist.
http://www.lileks.com/institute/frahm/index.html
Here’s a good one www.theonion.com If you’ve never been there it’s damned funny.
Here’s another www.redmeat.com Absolutely one of the funniest comic strips on the net.
And my personal favorite www.straightdope.com. Come on I can’t believe neither of you said it!
[edited to fix url-Czarcasm]
[Edited by Czarcasm on 04-27-2001 at 07:09 AM]
A Flash stick figure kicking major kung-fu butt:
http://www.tbcnet.com/~torx/temp/fight.swf
A hilarious video that’s apparently a major hit in India:
http://ebhon.jnst.uor.edu/~raveneye/geek/daler.html
(go to the bottom of the page. The first one’s the one I’ve seen)
Here is a few of my favorites:
http://www.iwin.com : Great game site.
http://www.pvponline.com : My favorite online comic strip. (Thanks to Esprix for bringing to my attention)
http://www.chasms.com : Online technical support tools. Very nice.
http://www.wizardworld.com : Online home to Wizard Magazine.
Can’t beat the Brunching Shuttlecocks. They’re great.
A large collection of humor, including the largest collection of “computer stupidities” I’ve ever seen.
Some of my faves are
http://www.ubid.com (online auction, better than eBay, IMO)
http://www.hotbar.com (allows you to add various “skins” to your browser)
http://www.passkeeper.com (download a utility to keep all your passwords in one spot, safely)
Max Torque showed me http://www.bad-candy.com a few days ago and I thought it was hilarious. 
Rose
http://www.once_upon_a_forest.com
this is… umm… interesting? and good…
Most of the great sites I get are on the SDMB. some are even other peoples homepages. 
http://www.geocities.com/sdpeoplepages/
A nice collection of pictures of your favorite poster.
How stuff works! very neat. I can pick a lock now 
http://www.utm.edu/research/iep/westtime.htm
Timeline of Western Philosophy.
http://socialcritic.org/review.htm
Some nice articles. (ok, im a geek)
Here’s a link to a great site. It has articles about fun things like anagrams, number games, lots of other good stuff.
http://users.aol.com/s6sj7gt/mikehome.htm
The world’s most useless webpage. You have to visit it.
http://www.go2net.com/useless/
Go to this page and click on the link called “udder insanity”. Ignore everything else. It’s a game. The object is to milk cows. If you can’t milk them fast enough, they explode.
http://www.designreactor.com/portfolio-game-main.html
So, what’s on your Hotbar? Currently my hotbar is Duran Duran. Love the band and my last name is Duran, so it fits.
97% of the questions on the board could be answered here:
http://www.google.com/
Do you have a cite for that?
Nothing on the browser here at work - they won’t let me download Hotbar, can ya imagine? - but at home I think it’s a peacful mountainscape. I like the nature ones da bestest.
In addition to fff.fathom.org that Opal mentioned above, there is a specific section of that site that is devoted to providing links that have been organized according to topic with descriptions (and some ratings) of those sites:
We have also had several threads on this subject, before. Here are some of the results:
What other websites/boards do you frequent?
More threads on this topic:
http://boards.straightdope.com/sdmb/showthread.php?threadid=15747
http://boards.straightdope.com/sdmb/showthread.php?threadid=55855
Other useful links I’ve collected here:
http://www.xrefer.com/ offers searches of a great number of good reference works.
I heartily second the recommendation for lileks.com. If you go, don’t miss the Gallery of Regrettable Food and the Gobbler–the Grooviest Motel in Wisconsin. I too visit this site every day.