Sites I Use
The People's Sprites: This site has a lot of sprites that just don't seem to come up anywhere else. All sorts of platforms, although many of the more common games aren't covered.
Pixel Perfect: A smaller site, but they have some stuff other sites don't.
The Shy Guy Kingdom: One of those all inclusive sites for sprites from most any era. Also has custom sprites, although most of the custom jobs require permission to use.
Sprites Inc.: A great source for Mega Man (and a smattering of Castlevania) sprites. I find that Mega Man weapons work great as spells.
Spriter's Resource: Another big site. Has some backgrounds, but mostly sprites from Nintendo, Sega, Capcom, and Square. Great for RPG needs.
Online Video Game Atlas: A site dedicated to mapping out games. While it seems like their intention is so you can find your way through some games and see what's up ahead, it's also a great place for screenshot maps.
DMFA: Ambaaaargh's web comic. It's got a whole, fleshed out world that only gets deeper (and funnier) as the comics go by.
Leftover Soup: An interesting, slice-of-life comic about geeks and gamers set is a close approximation of the real world. Well, a real world where people frankly talk about everything, but in a funny way.
Sexy Losers: The kind of comic that is simply laugh out loud funny... Just, not for the weak of heart.
XKCD: This comic is... bizzare, but it a good way. You'll start reading it going "this is odd," and before long you'll be laughing (and hooked).
Sites I Read:
AV Club: This site is my anti-drug... well okay, it's actually more like my pusher, since I regularly read it for tha articles about movies and video games and everything I'm interested in. And then I go out and buy the movies and the games and evenything else. Damn it.
Cracked: If you want to kill all productivity in a day, go hit this site. You'll read an article, and then find other articles from that one that share more information... and then soon enough you're lost for a day. But damned if isn't (educational and) funny.