Uncharted and Uncharted 2. I don't know why, but Crushing difficulty got really easy for me by the last stages of the game. You just have to master blind-firing and you've won. That said, the last boss battle of the second game is an exercise in controller-biting frustration.
Fallout 3 is another game which isn't all that hard - hot-keying stimpaks makes Very Hard a walk in the park. I was also pretty good at Bad Company 2 in all positions, but I don't play it often now so I'll probably suck if I started again.
Enough bragging, though. These are the games I'm awful at -
Stealth games. Pretty much all of them, except Splinter Cell: Conviction which is fairly easy anyway. I simply don't have enough patience for them. I still like them though - one of my favourite games is Hitman: Blood Money.
ARMA. I adore this game but it's hard as hell. I'm shit at ordering my squad in the heat of battle and I'm a danger to both sides when someone puts me in a helicopter. Still, that game is SO COOL. If you haven't heard of it, watch this all the way through.
Or if you can't be bothered waiting for the action, here's a more exciting one -