Take this as advice from a hardcore pc gamer that haven´t even touched a console prior to the 360 and then Wii. I have touched a gamepad of course since I used it in some games on PC like GTA titles and sport titles...
But really the main advice is stay away from console fps games! have you played fps games on the pc for years its just to hard not to compare them and being frustrated by the aim or the poor AI or auto aim or other things...
The action/fps games I have had most fun with is where I was more into the story, environments rather then the actual basics... Of course you will get better at it but you will never ever be close.
So I wouldn´t buy a console to play this type of games really. Though titles like Assassins Creed, Mirrors Edge probably there is of course somes where acrobatics is more important then aim. Those unless you have a modern computer you will probably not feel very handicapped buy a console.
As for Wii okay it´s not as precise as a mouse/keyboard but the aiming is tons better and it´s much more immersive![]()
I used to feel the same way when I had to get used to a controller. It's really frustrating going from a hardcore PC gamer to console. But you just have to get used to a controller and don't expect to be as accurate as a kbm. I prefer to play console games now because computer upgrades just got too expensive and annoying for me.