I have played DK but I didn't know that his up-b had super armor and can kill on ground! That just sounds fun got to try that.I have a few favourites but so far the one I play the most at the moment is Donkey Kong, I tend to approach with either his dash attack or just a short-hop back-air. I also use back-throw when they are at high percents and then jump off the stage to either meteor smash them with my down-air or forward-air though sometimes it can be hard to hit the right spot for the meteor smash. Another one of my strategies is dashing and then attacking with his down-b because either it gets you free damage and if they shield it will break their shield, so a free forward smash or even a kill, while his up-b might not be that good in the air it's amazing when you use it on the ground, I believe it has super armor and the first hit can even kill, it also sucks your opponents in. Donkey Kong is a heavy spacing character and he is very fun to play with, I'd recommend to give him a shot!
It feels more amazing when I do with with Dr. Mario. He is a lot slower but the cape reflect thing is much more satisfying. Especially against a spammy Lucario that charges b all the time.Mario is my main. I love doing that Down throw into up-tilt combo and also dash attacking and then chasing for a meteor smash. Mario is quick and has options for close and ranged combat scenarios, not to mention the wall jump and his recovery range is great. The cape is also a god send, I've gotten really good at using it and it feels great whenever I reflect Mega Man's fully charged side smash right back at him.
Zelda is the only character I face online that I hate facing. It seems that everytime I face a Zelda in FG mode I lose and they are a good player.I marked out when Mac was introduced to the game, and I told myself I was going to love using him, that he'd be my main, and sure enough, he's the one I use the most. His speed, his power, everything about him is great. He's really fun to use, and about his only downside is the terrible recovery. I'm also a pretty avid user of Ganondorg, Bowser, and Zelda. I'm not really that fussy when it comes to picking a character though, I'll play as anyone if I'm in the right mood. I tend to enjoy pressing random when I'm playing with friends or offline, and I don't really play online with randomers that often.