I think they're really fun.

I've only actually completed Mega Man II, III, X1, and X2. I've at least tried out the rest of the games (I own both Mega Man Anniversary Collection and Mega Man X collection), and I'm just not good enough to pass all of them. xD But, reading up on the stories of each game, I feel like they should've ended the X series at 5. :/ I could hardly stand X5 having Alia babysit you on how to do every single thing, and X6 was just even more annoying (apparently is was unfinished, which explains why all the level designs just seem like they were thrown together).

But, the one thing I love about the MM games is the music! Bubble Man's stage theme for the win, y'all.