The answer to me is quite obvious... Thatguy ahead of Fuse. I feel pretty good about myself to be mentioned as a good sniper from thatguy because in my opinion he does exactly was a sniper should. Let me explain what I feel a good sniper should do, and you'll see why it can be kinda hard and annoying sometimes
1. Be able to get the headshot, because that is going to help your team more so then body shots
b. Have more to your game then charge up behind an object and step around corner and fire shot, then repeat. Getting off many shots is pretty beneficial, along with moving between shots
3c. be aggressive!!!! nothing is more annoying then watching 4 snipers on your team play defense. I don't play sniper as much recently because i have too many defensive snipers that don't do anything to help their team. Push and take out the defense.
Lastly. Picking the right targets first. I watch too many snipers aim for other snipers. Do that only when he's going to kill you before you get a shot off. Other then that, kill medics first people
My favorite things about sniping are when the other team changes to either sniper or spy to try and have an affect on you. I think its pretty weak switching to spy and backstabbing the sniper with 2 sentries that kill you immediately
The best...
ThatGuy, Fuse, Hoostrax (can't believe only that guy mentioned her), dryft, Doobs (he left after I killed him once... sissy), cccp, firethem. Thats all i can think of, i'm sure i forgot someone.