(Oddly enough the 'Descent' series is an exception to that, I could play those for hours... But pretty much any other 3D FPS will have me looking for a barf bag within minutes)
Really? I got really dizzy the first time I played descent. But my fragile little brain was used to Wolfenstein 3D and Doom 1 when I played descent for the first time, so it kind of makes sense I guess. :)