I didn't really have a team in mind before I got the game, other than I wanted to unlock Diddy and play him. I ended up getting him, but I'm still sticking with my main man Bowser.
Captain : Bowser
Forwards : Toad, Boo
Defense : Dry Bones
Pros: Bowser is a monster to handle on the field and with his deke it's very hard to defend against him or to tackle him blindly. Boo is the dark horse of the game, since his skillshot is hard to pull off no one ever sees it coming and when done correctly there's nothing the goalie can do, Toad is fast and able to steal from just about any one and can usually be relied on to make the pass. Dry Bones is the ace in the hole, when nothing else works his speed and his skill shot are going to do it. There's also something satisfying about setting Kritter on fire.
Cons: Bowser is slow, and a poor passer. He can't move the ball at all when he's in trouble and his passes routinely get intercepted. His special is hit or miss, if you don't get every one on the screen then some one is going to take the ball -- plus you usually end up setting just as many team mates on fire as enemies. Outside of bowser it's a pretty weak shooting team, it's more about getting ball possession than putting it into the net.
Oh, and I have the most wins over Wario, and the most losses against Luigi, if that matters.