My favourite chars in Brawl are Captain Falcon and Olimar.
It's difficult with Captain Falcon ... I like him a lot, but to me, it seems like he lost strength compared to Melee. At least it seems so to me, I owned everything with my good old Falcon. It's different in Brawl ... ): Aw, I guess I should stop complaining and start playing seriously! (:
I got some issues with Olimar too - First of all, I really like his grap attack. The range is very cool and I love Olimar for that. And to really make him damage is no problem, but when it comes to smashing the enemy out of the stage, I fail. I'd really like him to have a stronger smash attack ...
Yeah, I'd also say that Mewtwo and Lucario have a similar move set. Maybe because they are (more or less) similar Pokémon? Or because the creators were lazy and didn't want to create an entirely new set for Lucario.