SMK: Battle mode was pretty tough. I liked the music, though. I played it some with my brother when I was younger though.. Also, I like how the balloons (balls?) are on the ground instead of floating the head. Haha.
N64: Music was pretty good. Battle stages were fun, too. Played some battles with my friends when I was younger. Characters had their own colored balloons.. (Luigi was blue, Yoshi was green, Peach was pink.. etc.)
GCN: Interesting, but gets boring overtime. Some of the stages were okay. Played a few times with my brother. Also, some of the modes were cool. My favorite is the bomb-omb blast because you can spam bombs.. in which was awesome.
Wii: Well, I hate the fact that you are forced into teams. That's the worst idea yet. Some of the stages were okay. I didn't really like the Coin Collector idea. At least you can battle with the computers for the fun of it or train. You had to choose either standard kart or standard bike. Battle mode would have been a lot better if you can play free-for-all. Another good thing is that you can play online.. but whenever I play, I usually encounter hackers. <_<
I didn't review DS or GBA because I never played them.