Which do you prefer? Robots or spaceships?
I like both, but I honestly prefer robots. There are so many cool robot enemies, but never enough neat robot players! Even better though, robots that convert to ships!
Recommended shooters with robot player characters:
Sidearms - Both arcade and on our beloved TG16!
Lords of Thunder - I know it's a human in magic armor, but it still looks the part!
Spriggan - I don't like it much, as it's too hard for me, but no doubt it's a robot!
Spriggan Mark II - I like this one better! Blasphemy, I know.
Out Breakers and Last Breakers - PC 98, with no questionable content as far as I know.
Macross shooters! SNES, TG16, Saturn/PSX, NES, PC88, etc. etc.
I know there are more, but this is a good short list.