Like many have said, Mega Man 2 was the biggest improvement in the series. Capcom seems to have this way of nailing it on the second game - Mega Man 2, Street Fighter 2, Ghouls 'n Ghosts, Resident Evil 2...

I've played/beaten all but MM11 (have it, just haven't gotten around to playing it yet) and I haven't finished MM10. Mega Man 3 is a pretty close second but Mega Man 2 is my pick as it had some of the best robots and bosses of the series.

Just not Devil May Cry 2.  

Haha, definitely an exception.

I think Powered Up should be in the poll, and honestly may deserve to win. 2 has better level design/bosses/etc, but the replayability and features of Powered Up may push it over the top. A shame they didn't Power Up Mega Man 2.

My original MM Ranking:

2>9>11>5>6>4>3>10>7>8>1

I think 3 is overrated. A long time ago I thought it was as good or better than 2 but while the core concept is great (more levels, more moves, Rush features), the actual level and boss design isn't as good and subjects you to way more BS/unfairness. 1 and 3 were both really bad for that.

I also didn't much care for 7 or 8. the art style, speed, gameplay, and feel of those games just felt off. Not bad games - none of them are - but wow I just didn't feel right playing them.

the first 6 were all immensely solid. 9 was outstanding, 10 was pretty good, too. 11 was also outstanding and the only non-8-bit game in the series I loved. I'm actually kinda surprised that, as of the time of this writing, not a single person has voted for 9, but there is a vote for 10.

I HIGHLY recommend Mega Man 11. It probably has the best game feel of the franchise (As blasphemous as that feels to say). It's tough but fair (something not every game can balance well), and it looks and sounds amazing. From a modern lens it's exactly what I think the series needed to be in 2018. As you can see from my prior post, it's in my top three. 

I beat 1-8 on the Gamecube collection, and then 11 on Switch... Never beat 9 or 10.

7 is the one that sticks with me most. One of my favourite soundtracks ever and I just love the look and feel of 7.

Someone said that 9 and 10 have higher difficulty then the rest, and I want to second that. To me both felt much harder than 1-8.

Also, I like 11 a lot but I was disappointed by the music in my first playthrough. Not a single track was memorable. But, I have replayed it several times now and I got accustomed to the soundtrack. I like Block Man's stage music the most, but Fuse Man, Tundra Man, and Bounce Man have nice tunes, too. Also, the stage select theme rocks.

That one was certaintly a number two...

OT: Megaman (all the 2D side scrolling sagas) is my favorite franchise ever, and speaking of classic Megaman, I'd rate them as:

2>3>11>4>1>7>8> Everything else.

For me a thing that puts MM3 in the bottom of the list, of the MM games I’ve played, is that you have to play each level twice (if I remember correctly) or something simillar. I’m usually not that fond of games that artificially lenghten the game in that way and no it’s not the same as backtracking in open world games like original Metroid.

I much prefer MM1 over MM3.