You can't play Y2 I'm afraid. It's one of the few games where the copy protection has never been broken. You can boot the game, watch the intro and begin the first stage, but it will be unplayable without an original disk in the drive. I do have a capture up on youtube, as I've never met anyone else with a real copy...
For MIDI:
Neural Gear (CM-64)
Metal Orange EX (SC-55)
Group X (SY22)
SION II
Choujin
Gemini Wing
Angel Dive (SC-55 and MIDI only, there is no internal music)
Choujin and Gemini Wing support the CM-64 PCM expansion cards. Choujin has 7 different music configurations by itself. SION II was a free game made by a magazine, it has completely different music for each module made by different people. (play at 10mhz only or the music will be out of sync) The SY22 is a very unusual keyboard that blends FM and Samples via Vector Synthesis.
I'm assuming you don't have the hardware for a lot of the above, but I have vids up on youtube about most of them. Also SFII' SSFII, Daimakai are actually pure GM, not GS, and the SC-55's GM support is a bit shit. Greatly benefit from a better module like Yamaha MU100 and after, or Roland SC-88 and after.
The games Afterburner, Thunder Blade, Super Hangon, Neural Gear are all meant to be controlled via analog joystick, hence the digital controls are a bit shit as they were just tacked on. You can change speed in AB when using the mouse by pushing the XF keys, they are presets for 25% speed changes iirc.