Final D is overall probably your best stage, and as such, I haven't been to a tournament in well over a year that my opponents didn't ban Final D. My favorite stage personally is Pokemon Stadium because if you know what to do, you can combo almost as effectively as you can on final d. What's even more, you can potentially combo characters that you normally wouldn't be able to because of the platforms helping you out, like against sheik for example. It just kinda sucks when the stage changes..
Yoshi's isn't TOO bad, but the highest characters in the tier list do well there, so I wouldn't personally reccommend it. It might be ok against someone like Jiggs though for obvious reasons..
Battlefield, I can once in a great while still pull off a 0-death here, but it's completely dependent on your opponents DI. I also don't like that it's hard to ledge tech here, i usually ban this stage.
FoD. I don't like this one either...It's not TOO bad because you can up b through the platforms and you can easily ledge tech here and giant punch kills pretty early here, but overall I wouldn't ever take anyone here.
Dreamland, I like this stage. I counterpick here sometimes. DK survives for stupid long here. I can usually survive to almost 200% here. Your opponents survive longer here too, but i'm pretty good at edgeguarding, so I like the trade-off. It kinda sucks against campy opponents, but if someone camps you, just keep charging and releasing your giant punch constantly.
Kongo Jungle 64. I don't really like this stage...You can do some pretty cool stuff here and survive a long time, but idk...i personally just don't like it. No ledge teching and the curved stage are kinda lame...
Brinstar. This stage is pretty good against like...a falco or something, and is overall a not too bad stage...Bum used to love counterpicking people here. I've done it a few times, but it's generally not one of my first choices. Giant punch ***** here though