I have been a huge Megaman fan from when I was a young lad. Megaman 3 was the first game I have played back on my stepbrother's NES and the one game which cemented my love for videogaming.
This game is a true godsend. Everything about it oozes perfection, from the enemy A.I. to the controls. It's also quite challenging (which you don't see very often in many action-oriented videogames anymore) but at the same time it's fair. I also love how you can use the weapon you acquire form defeating the boss in this game in the other game you've made.
Cheers to you, good sir!