Are there any, in your opinion? Why that specific game? Anyone here already into that business?

I've seen someone doing a Fallout speedrun in about 10-15 minutes. Think that you can still find the vid over the webz

You could try to beat this speedrun of VVVVVV:

http://www.youtube.com/watch?v=NldVS4YZz5o

The only game I ever speed ran period ever was Duke 3D which I can only do because I happen to know where EVERY DAMN jetpack in the game is. I can't find my car keys, but I can find Duke's jetpacks.

Truly amazing, the time and effort these people put into these speedruns. I would really like to get into it, but I also want to stick to my 'no DRM' policy, so I'm having a hard time picking a game :D

Definatly System Shock 2 and Deus Ex.

Well, that depends on what "worth it" means to you.
I personally would like to see more speedruns of Giana Sisters:TD.

I would recommend to start with a platform game:

Escape Goat
Giana Sisters: Twisted Dreams
Earthworm Jim
Rayman
VVVVVV
Volgarr the Viking
Pid
Mr. Bree+
Treasure Adventure Game

I'd like to see a Descent speedrun, but noone ever attempted it even on SDA :\

XD Descent is fast enough don't you think? You try to speedrun it you are likely to go to plaid.

Any of the Duke Nukem games, Realms of Chaos, Blood, Shadow Warrior, the Descent games, and Another World.

Total deaths: 21
Hardest Room Tower: 30 deaths

What's up with that?

Too bad they are not on GOG, but the original Prince of Persia (1989) and Prince of Persia 2: The Shadow and the Flame, of course :-D

I think it really depends on which title you can have fun playing over and over again. I watched this run of MDK recently, which was interesting.