Bullet Chat - Just like chatroulette, only way better. You can swap files, use a whiteboard, and add people you meet to a buddy list.
Interstitials - An ad-exchange network for full page ads. If you are a webmaster that's strapped for cash but still wants to promote your product, you can use this service to serve ads and earn new visitors. Free traffic!
Snes'O'Rama - One of the oldest and best ROM sites out there. One of my personal top 3 picks, with a gang of ROMs for your downloading pleasure.
ROM Collector - A cool site where you can purchase ROM sets on CD for a nominal fee, mailed directly to you. Very cool for the avid collectors out there.
GameBoy Advance ROMs - This site specializes in GBA ROMs. They have anything and everything related to GameBoy Advance.
ROMNation - Probably the 2nd most comprehensive, easy to use, BIG romsite on the 'net. Thousands and thousands of games for dozens of popular systems. Top-notch quality emulation.
TheROMs.com - Thousands of ROMs, hundreds of emulators, zero BS.
RomCenter - Audit and repair your roms with this program. Site also hosts hundreds of games available for download.