Number 5: Pacman; Okay, I'll admit that Pacman's appearance in this game is...odd. But it's a good kind of odd. His attacks are decent at best, but when it comes from recovering from a nasty fall, it's easy to get back up. Though his most useful attack can be stopped in it's tracks (power pellet), his Pac-jump will save the day. A combination of both will make it hard for him to fall, or make him exit stage left or right. He's the kind of fighter you want to send flying up. Just look out for his Fire Hydrant attack.
Number 4: Bowser Jr. & the Koopalings; I expected each one to have their own exclusive attacks, but no. Each one has the same moves. Really awesome moves. With the help of the Mini-Clown Car; chainsaws, cannonballs, drills, more cannonballs, mecha-koopas, a fork, Big-Wheels, boxing gloves, an extendo-arm, a hammer, and even a Lickitung-like tongue attack make the wackiest attacks the strongest. The clown car dash is easier to control than Wario's bike, and in the event that you fall off the stage, Abandon Ship is your best option. Plus the now airborne koopa can then kick ass with their hammer. The clown car will explode in the process, making it an explosive hazard for anyone beneath it.
(will add next 3 later)