JVC X eye

region patching is only for MegaCD/ SegaCD.
You still need to bypass the cart lockout - not sure whether it's necessary unless you have JPN/PAL carts that you have to play

 

Silpheed is great but gets harder as you progress.

 

People are paying 300+$ for Wondermega 2, which is basically the same thing.

Not that easy, it won't work for all games (you have to change the bootcode, not just a few letters).