Aside from Legends, not really. If I recommend anything, it'd be the first two X games (although I still hold X3 near and dear to my heart) and X4. The classic series kinda goes without saying. The Zero series is great, but far from my favorite for reasons of story, audio quality, and art style. If you're fine with all three, then you're in for a really enjoyable spinoff you can gnosh on during road trips or on your Game Boy Player. I can't recommend ZX much, since it's mostly a tired bastardization of the Zero series. Battle Network 1 was actually a pretty fun romp, but I just didn't get into it that much and stopped there. I don't even have the cartridge anymore.
Most people already know and have played Mega Man, but his most recent games leave too much to be desired. They're just not recommendable when it comes to enjoyment. X7 had solid potential, but controls like a stubborn cow, sound worse than one, and is the runner-up for most misleading title/box art ever. X5 has issues, but you can get something out of it before forgetting about it; I'm actually a little nostalgic for it despite it being a bad X game. X6 I can only recommend to hardcore MMX players who enjoy punishment. X8, while decent, isn't terribly remarkable to me. The visuals come off bland, the gameplay is okay, and the story's too insubstantial and recycled to matter, but the music is pretty damn good. Command Mission is an interesting title, but only recommendable to X fans.
As for the aforementioned Legends, I consider it an underrated gem and a fresh new take on Mega Man, but even it leaves some things to be desired. It makes a little too much use of empty, meaningless space and empty ambience to go along with it, but this only applies above ground. The real meat of the game is underground: fighting Reaverbots, finding hidden artifacts and parts/zenny for weapons and armor, and overall completing the objectives of the game. The town's nice and having an outside to explore is likewise nice, but most of it comes off as filler. I find this part of the game really hard to criticize, since it's part of what gives Legends a lot of it's heart and charm, but for the sake of gameplay, it needs some refinement and either additional details or trimming of space. If the game could've made me care more about the townspeople and made them seem less like almost-stationary automatons, that would already help give the game more charm and give the player another means of reward feedback for his efforts and exploits. Legends had charm, heart, and good gameplay, but it needed more character and smoother controls. It needs a stronger taste to it. It won't do well to just be pleasant, not when it's Mega Man. It's because of these deficits that, while still a beloved Mega Man game, Legends has not aged too well to most people. I can pick it up and play anytime, but I can't say the same for everyone.
Considering all this, recommending Mega Man is only hard because there's not much to recommend that hasn't already been played to death. We just haven't been getting a steady stream of great games, and it's hard for Capcom to do because there are now six seven mutually exclusive subfandoms to cater to.