My favorite male singer so far is the beatbox guy, his singing voice is surprisingly good, plus he's confident enough to do something as crazy as beatboxing on national TV, and do it well. Didn't like the guy who made the teletubbies crack at Simon Cowell, that seemed like a graceless cheap shot.
Seems like there are two girl singers that are actually good.
Regarding Mr. Cowell, more so than ever, he seems to be the only competent judge. I used to watch and think "this guy is a jerk", but now I'm watching and realizing "No, he's being honest. He might not be tactful, and occasionally he twists the knife a bit, but in the end, he's giving it to them straight."