Hmm... I've been working on a few of the classic Mega Man games.
Let's see...
On Mega Man 3, I beat all 8 Robot masters. and then, there are 4 levels that you have to replay, bu they are supposed to be harder. I beat one of them. so, I just have to replay Shadow Man, Spark man, and Needle man's levels, and I'll be good to go. I don't think those 4 levels count as part of Wily's Castle, though. I'm not sure. Does anybody else know?
Mega Man 4, I only have 1 more Robot Master left. (I forget which one...)
Mega Man 5, I beat all 8 Robot Masters and I just entered Proto Man's fortress.
Mega Man 6, I beat 2 Robot Masters. I bea... The flame one (I forgot his name), and Centaur Man. So, only 6 more Robot Masters to go.
Mega Man. That's right, the original Mega Man.

I beat all 6 Robot Masters, and I'm at Wily's Fortress. But, Wily's Fortress is super duper hard in this one. Does anybody wanna come over and help me? Lol. (jk) But, yeah. I gotta look up a walk through or something. I usually get stuck at the part where you have to freeze the flames and jump on them. Mainly because I usually freeze them at the wrong times, and then run out of energy with that weapon...