I never had issues with dizziness ... until games started using an over-the-shoulder camera. Basically, if the character is too far removed to the side, I stop connecting my input with their movement. It feels like I'm here and there's some random guy right next to my left who mimics my movements and also I'm incorporeal. It's a sort of uncanny valley territory - if the camera is just a bit to the side - no problem; if it's a far-away but centered behind the back - I'm fine; if it sort of tries to hover to the right, but swings around (Brutal Legend does it) - it doesn't bother me. But Gears of War is practically on the edge and I can't play it for long.