At this time, I'd say there are two characters in the roster that are very heavily underrated:
![Megaman :4megaman: :4megaman:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Wii Fit Trainer Female :4wiifit: :4wiifit:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
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This character reminds me a lot of Diddy in the early Brawl days. Most people though Diddy was slightly above average at best until some top level players mastered his glide toss blew his metagame wide open. I think the same will eventually happen to Megaman. He has crazy good glide toss and footstool options that put most of the cast to shame and it's going to be exciting to watch this character grow. Like Brawl Diddy, it may take a couple of years for him to really get off the ground though.
Aside from Ike, she's arguably the character that has improved the most from the patches. In the last major patch, nearly all her major problems were fixed (weird grab, lack of kill power, extremely precise hitboxes, etc) and she's almost like a whole new character now. Her tool kit is pretty impressive too:
-Two air stalls.
-Two projectiles that can reasonably kill.
-Two options to heal health.
-Three spikes.
-A move that buries people.
-A move that boosts her knockback.
-One of the best wall jumps
-Some of the best ledge trump options in the game.
-Deceptive hitboxes with weird knockback trajectories.
-A recovery deceptively good enough to where she can recover from the bottom corner of Smashville.
-One of the best jugglers in the game.
She practically has everything now aside from a decent approach (but she can force her opponent to approach instead) and a set up grab. This being said, she's like a less threatening version of Shiek and only a few of the high tier characters are really holding her back at this point.