One of my best friends couldn' play Half Life 1 or 2 'cause he ended up pucking everytime :D

I read that some people are helped by taking anti-motion sickness medicine... like for cars and plane... if this works for everybody I don´t know but its worth a try... I also hear the droppes are better than the pills but I have never had this problem si I don`t realy know... 

yes i though it was just only me doom on the snes makes dizzy and lightheaded

The original poster is suffering from an optical illusion not a physical defect. Their brain is seeing the image but misinterprets the data, and when the rest of the data presented from the rest of the body does not match the data from the eyes the conflict feels like motion sickness. Ironically the game developers have done too good a job in simulating reality.

What the original poster needs to do is convince their brain to stop registering the video image as real data with depth, and more like it registers a painting with only implied depth. Basically the game must be played in a way that was not intended. Here are some techniques that should help.

Screw up your color settings. Try to get a screen that is shaded green, blue, or red. You may not have to go to far to get your brain to perceive the image as flat. The best seems to be going for black and white. Work the contrasts and the brightness. Get some glare going in the room you are playing in. Most players find this annoying, because it ruins the immersion. You actually want to turn your immersion back. Play the game at a angle or greater distance. This will help you to differentiate the television as a distinct entity. Finally my personal favorite the good old eye patch. Depth perception is overrated in gaming anyway.

One of these techniques should help you with your problem if not going looking there are hundreds of techniques.

I never had a problem like that but my brother gets headaches when he plays some FPS.

With a FPS I've never had motion sickness problems. Not even with Half-Life 2.

Now with Mario Galaxy... that's a different story.

My wife already thinks I'm out of my mind for devoting as much time as I do to video games.  If I start wearing an eye patch she might have me involuntarily committed.  But your explanation is interesting and I will try messing around with settings to see if it helps.   

the first and only time was the first time i played resistance fall of man, I got over it in like a minute. lol

Same here . Afther playing Half - Life ( but just the first one ) for more than an hour I got pretty damn sick . On the other hand I can play Quake 1/2/3/4 or HL2 for 10 hours and still nothing :)

I've never experienced motion sickness from a FPS, but I haven't played too many of them. The only time I experienced motion sickness with a video game is this one time I plyed Guitar Hero on this giant projection screen. I really thought I was about to throw up, but fortunately, I didn't.