Bionic Flea was the first character I made on live and first again when I came to HC. He's Invulnerable/Super Strength tank and has done everything in the game. He is definitely my signature character.
Between HC and other servers I have about 160 level 50s. They each had their time in the sun as I leveled them and they still get brought out periodically to fill a needed role on a team or just to play them for a bit.
Looking at my list of characters, I seem to play support more than meatshield or DPS, so I have a lot of corrupters, defenders, and controllers. But I have more than one of each AT and I think I have tried all the power sets out, other than Arsenal Assault, with a caveat. If I played say dark blast on a corrupter, I consider that covers dark blast for defenders, blasters, and sentinels. Same with armors and control sets.
I don't think of any of them the same way I think of Bionic.