Wario 40-60
Wario is an odd *******. He is one of the few characters that does not have problems koing you around 110-120 due to his uair and fsmash (the fart is easy to upb brake, but technically worth a mention). he can also chain grab you to 105, eat (literally) your shield, spotdodges, air dodges and rolls, and live past the majority of the cast.
Sounds REALLY bad right? well, sort of. You have the advantage of guaranteeing you punch out of a grab release for a free 30-25% (or death after about 70%), as well as your fsmash (free 20%), Usmash (death after 86%), and dsmash (death around 110 or so). you also have a large range advantage, as the stubby little guy tends to lose when attacks collide.
Now, hitting him seems a lot harder than it actually is at first. he's going to float around and try to bait your attacks so that he can punish, don't fall for it. when he gets into the air, keep your back turned away from him and wait, don't let him get directly above you, if he tries to come down on you, utilt him, if he looks like he's trying to get directly above you, jump straight up (maybe away but NEVER towards him) and wall with bairs. it makes a good wall for him and forces him to give up the air camping. If you run out of stage, run under him when he's at the height of his second jump.
on the ground he's going to want a grab, this makes it easier to grab him, however you have to be extremely careful or you'll wind up taking 105%, other than grab on the ground he doesn't have much (fsmash is more of a punish), and will likely SH aerials and the bite, utilt or high angled ftilt work best when he does this, preferably utilt.
The object of the game is to wall him off and not let him get in, but that can be very hard when you face a good wario. fortunately there are like two good warios, the rest of them you should be able to wall easily.
40-60 against good warios (both), 60-40 against the bad ones (note, they'll try to grab like no other if they can do the cg. serious falco syndrome with these people)