My favorite overall champion is Singed. He's such a good tank and he's also quite trolly. Poison, flip, run away, repeat. I've carried games as singed, mostly with assists, but I've had some crazy games leading the team in kills with singed. It's an odd feeling knowing that if you're not there in every fight, your team will die a horrible death. You can get that effect with almost any champion if you're doing well enough but, if feels like it happens every game when I play singed. I feel like I'm babysitting the entire team

My favorite Carry is Caitlyn. She's just fun to play and really good all around. She has a strong early and mid game, setting you up for a good late game, and she can even play mid. She's probably my favorite mid champion despite the fact, in the current meta, she isn't supposed to go mid.
My favorite top laner is Riven. She's just fun to play. I'm not that good with her though

My favorite Support is Zilean. BOMBS EVERYWHERE.