Fox: Naturally, because he is the main character, all of his stats are balanced at medium-level. He is a formidable pilot in both means of transportation, and his gunmanship is at level four.
Krystal: Her stats are a slight bit below average, but she makes up with a double-barrier bonus. This may not seem all that special at first thought, but this extra boost can give you the game in multiplayer mode.
Slippy: An excellent Landmaster pilot, and a decent jumper, too. I prefer throwing others off with his high squats in Sniper Showdown, then I approach and fire a quick-shot. He's a great source of life, and quite handy with a booster-pack. I would recommend him.
Falco: Fast, swift Falco is always an excellent choice for aerial assault, and he's not bad on-foot, either. His speed helps dodge blasts, and that's a requirement for a guy with a small life span. Despite what his stats depict, he's not that bad in a Landmaster.
Peppy: Similar to Krystal, but a bit worse. Made for high jumping, but that's about it. Basically, the strategy is grab a booster-pack and a rocket launcher, then sweep the grounds from a high point. Or dodge attacks by jumping and fire full-scaled shots with a blaster. Don't rely on Peppy to escape from a sniper, though.
Wolf: Wolf has the best stats in the game. I would refer to him as an improved fusion of Slippy and Falco. The life is maxed as well as speed and aerial piloting. He's not that good in a tank, but is strong and resistant enough to take them out on-foot. The jumping is rather off, but when you perform a long jump, it surpasses all others except Pep and Slip.
If you see me posting, it's because I've been asked to. Which I guess would mean I'm taking requests.