Trouble Shooter 2!
When I'm not in a Thunder Force 3 or TF4 mood, this is usually my next go to game in the genre for MD. It's one of the better 16-bit shooters I've played, with great variation, rocking music, fun bosses, cool weapons and all of that. It's also not that hard compared to most shoot 'em ups, though still provides more of a challenge than the prequel. To be honest the endearingly silly anime setting is also a big reason for me to come back to it. Only thing missing off the top of my head is a 2-player mode really.