That's opinion, man.
I only use sword types, because they're more variable with their strengths. I like Marth and Roy, because you have more options with each attack. Left and right B give you LOADS of different patterns you can break into, plus they have that counter ability which works even against attacks like green missile.
Besides, there is no real "skill" in a game like Smash Brothers anyway, its all timing and remembering which two buttons to mash. (part of the reason I don't play the game much.)
I hope they solved some of the problems that I found in Melee. Like, if you charge a smash, your opponent (if they're worth anything) can see what you're doing and get around it every time. They should make it so like, if you change which direction you're holding while you charge, you switch to a different smash, so you can adapt to your opponent not being a total etard and moving around a little. In brawl I hope they change a few things too. For instance, instead of having left and right A/B be the same attack, make it so if for instance, you are facing right, and use left A/B you get a seperate attack. And make it so you can do combos, so when you do like, right+B right +A you get a different attack then just hitting right+A.