You (almost) can't go wrong with stage choices for DK, because of his sending power and his recovery he tends to get all of the benefits to a stage with none of the drawbacks.
Starters
- FD is one of his strongest stages because since it's level it more consistently puts the opponent in danger of getting grabbed, and of course his grab game is one of the best in the game. Expect people to ban that one a lot for the same reasons they would ban it against Ice Climbers pretty much. Don't take characters like Sonic or Mewtwo or anyone who you can't capitalize off of grabs well here.
- Smashville is another flat-ish stage, not much to say about it really. Most neutral stage in the game. It's not going to affect you negatively if you wind up here but you can typically counterpick stronger stages.
- PS2 is pretty decent against fast fallers because there's no top platform for them to tech away from uair juggles.
- Battlefield is a good option defensively against characters like Marth BECAUSE of the top platform; since he can't KO that well at high percents you can up-b to the top platform while recovering as a mixup.
- Yoshi's Story is a good option against light semi-fastfallers because jab jab nair KOs at stupidly low percents there. Obviously avoid it against characters that can KO you at stupidly low percents right back (Marth, Ganon, Ivysaur)
- Fountain is pretty good for spacing tilts and jab around the moving platforms but it's one of his weaker stages overall. I tend to ban that one just because I don't like it in general.
- Dream Land is another good stage because DK is absurdly difficult to KO off the top here and his horizontal recovery is long enough to recover from almost the side blastzones, while his own sending power is still enough to end stocks reasonably early.
Most likely you'll wind up on Smashville, PS2, or Battlefield in game 1.
CPs
- Lylat is less terrible for DK than other characters because his recovery lasts so long he doesn't get denied by the lip as much and the positioning of the platforms is pretty good for his nair. A lot of people will ban that one because they hate it more than you do.
- Green Hill Zone is what I usually counterpick, it's a mostly flat stage with narrow blastzones so he can get both grab combos and absurdly low percent kos here.
- Skyworld is another one where DK's recovery around the ledge screws him less than it does other characters, and the side platforms make his full hop nair pretty scary. The size of the stage also helps his longevity.
- Yoshi's Island is usually my other ban because the ledges make it tricky to edgeguard vs certain characters and the platform isn't optimal for his combo game.
Usually in the later games you'll see FD, Dream Land, and/or Lylat banned most often so you'll want to counterpick Green Hill Zone or whatever neutral you feel most comfortable on.
If you're banning you generally want to knock out Yoshi's Island, Yoshi's Story, and/or Fountain, but a lot of the time you might find yourself banning stuff just to move the set along rather than actually not wanting to play on it.
