My last A rank was hard mode for Cosmic Wall. It wasn't so much that it was a hard level, but it was an incredibly long level. Somehow I managed to get all 461 rings on it. I was shocked when it said "perfect."
But I really despise Knuckles and Rouge levels. My roommate, however, is really good at them so he did them. I never liked those levels as a kid and I still don't like them. The Sonic and Shadow levels are way more fun and even the Tails/Eggman ones are decent.
New Jersey Devils 2012 Eastern Conference Champs
New York Giants 07-08 and 11-12 Super Bowl Champs