Well I am, in my opinion, a pretty good player. The only adc I can legitimately play well is KogMaw. I like to play Kog because he isn't super easy, but he's not hard either. The only challenge is the beginning, but a great support changes all that. The people I support with are Nami, Lulu, Leona, and Kayle. Lulu is my favorite, but I am really aggressive with her. I'm aggressive with Leona as well, but not in the same manner because I more try to set up for kills and save teammates, which happens entirely too often. I'm sort of half and half with Nami, I don't really have a side with her. I mid with Annie, Karthus, Fizz, and sometimes Syndra, Ziggs, and Veigar. My favorite mid is Annie due to her being a bit under played, so people are less prepared to face her. And I've been told I'm pretty good with her due to my major amount of practice with her. My second favorite mid is Karthus. He's just awesome. Only one problem though. People always expect you to ult every 20 seconds and if you can't do it then you suck. The tops that I play are Chogath and Teemo. I like Teemo more because people always attack him at any point because he's so squishy and you end up with a kill. I like Cho because of his ult making him physically bigger and it does true damage. You can't go wrong with true damage as Darius proves. That leaves Jungle. I don't jungle because of a horrible experience with Skarner. I had a absolutely horrid leash and I died because the golem beat the **** out of me. That quite literally threw the whole game for us because I didn't know how to recover from that. I mainly do 5 v 5's on Summoners Rift, but I play everything else just a bit. (I secretly find Dominion quite fun, but absolutely no one wants to play Dominion anymore. I just don't get it.)
