Little Mac. I hate fighting against him, and I hate losing to him. I train my Fox specifically to deal with Little Mac, I hate him that much.
First off, he's super annoying to deal with. The first time I played against Little Mac was a level 9 CPU. I couldn't beat him. xD
It turned out that I was awful at the matchup. That and it was my first time playing the game. I finally started winning consistently, and thought I had Little Mac in the bag. Then, I start playing online. After a week or two of playing online, I faced a scrubby Little Mac. Like, a super scrubby Little Mac. The dude was terrible. I two stocked him every match (with Fox, of course. Fox is the only character I like for the matchup). Then, this match happens. This certain match. This scrubby, obviously inexperienced Little Mac, two stocks me, and only took sixty nice percent. He beat me in under a minute, and the second kill was a KO punch. Then, whenever I was on the character-select screen, I looked down and saw that he was still looking at the results, and was there for about a good ten to fifteen seconds. That made me mad, because I knew that meant he was saving it. I about threw the controller. Next match, I two-stocked him, then turned off the Wii. I had never felt so humiliated.
Ever since then, my Fox has NEVER lost to a Little Mac. I would complain about the KO punch being OP, but I don't want to be put in the same group as the people who complain about wobbling .
EDIT: My worst matchup is actually Link, but anytime I lose to a Link player, it's because they were actually good. Link is fun to play against, and isn't annoying to lose to. All Link players are really good actually.
Fox because it always feels like he has lag advantage and can punish all lag based mistakes but I can't punish his
Haha! Even as Fox, Link's my worst matchup actually.