Games and Other Time Wasters

Addicting Games - Links to a great many internet games, most Flash based. I especially recommend Mini Putt and Curve Ball for wasting a few free minutes.
Bored.com - There're about a million things to do here if you're bored.
Computer Stupidities - Tales from the trenches and front lines of the IT and technical support world.
Customers Suck - Tales from the front line and trenches of the retail world.
Fantasy Film League

Movies and Music

Fan Films - Fun little films made by and in the style of popular films, mostly Star Wars. Some are really quite good.
BeatBox.tv - Ever wanted to learn to beat box? This site will show you how, and do it in style.
eMusic.com - Until recently, eMusic offered unlimited downloads from their library of mp3s (lots of older and lesser known stuff) for $9.95 per month. Now they offer a limit of 40 tracks for the same price. Still a good deal for legal, non-DRM mp3s, but no longer a great way to find new artists (when every download counts, you're less likely to take a chance).
The Internet Movie Data-Base - The single best source for information on movies. You can search by title, actor, director, and even dialogue, making this the tool for quick and easy, if not indepth, movie research.
MC Frontalot - MC Frontalot is the ultimate geek rapper, and even calls his style "nerd core". All of his tracks are available for download from his site, among them the "official" Penny Arcade theme song.
MP3 Newswire -

Reading

Amazon.com - The online source for books, music, movies, etc. They have good prices, fast shipping, and a very informative site. I've found that they have especially good prices on computer books, and they've recently added martial arts gear to their offerings.
Audible - For a $16 a month membership fee you can download two audio books, out of a library of thousands, per month. Or you can buy the books one at a time. Either way, you can then download the books to listen to on your computer, or on many mp3 players (including the iPod), or even burn them to CD.
Book Pool - Discount technical books.

Writing

Grammar Lady - A site all about proper grammar. Yes, I enjoy things like this. Yes, I'm a geek.
Guide to Grammar and Writing - An excellent resource for all your grammatical needs.

Weblogs and Articles

Eat My Words - A weekly opinion article by former Movie Punks artist/writer Carrington Vanston. Intelligence and strong opinions, apparently it is possible.
The Talent Show - An entertaining liberal weblog that comments on the latest political developments.
WilWeaton.net - The weblog of Wil Weaton, possibly best known as Will on Star Trek: The Next Generation. Wil Weaton is insane.

House and Home

Als Home Improvement Center - Lots of informative articles covering everything from wallpapering to soundproofing.
Hammer Zone - A page full of helpful and informative articles on home improvement.
TLC's Trading Spaces Fan Site - A site dedicated to The Learning Channel's popular show Trading Spaces. Not only am I a fan of the show, but there're some great ideas and how-to type information on the site.
Soudproofing 101 - An amateurishly designed, but very informative site all about practical soundproofing (there's a slightly technical discussion of this here).
So You Wanna... - An interesting and entertaining series of "how-to" type articles covering a huge variety of topics.

Pets

The American Kennel Club - A great source for dog lovers.
Easy Insects - If bugs are your bag, this is a good place to start.
Mike's Praying Mantis Page - Praying Mantises are really cool.
Purina.com - Fantastic information about the care of both cats and dogs, as well as a dog breed selector feature which is very cool.

Martial Arts

Super Action - T-Shirts featuring martial arts inspired designs.
The Portland Quest Center - Martial arts school I attend in Portland Maine that instructs in the art of To-Shin Do, a modern form of Ninjitsu (or Ninjutsu, or Ninpo, whatever you want to call it).