Ikaruga is definitely one of the best. Got a copy for my Gamecube ages ago when it came out and it's sooooo good.
That said, if there's one shmup I would recommend over all the others, it would have to be Viewpoint. I'm not gonna type up all the reasons why it's awesome again, so if you're interested in it, you can read my full review of the game here. It's insanely difficult and as awesome as they come.
__________________
Talent, vigor, drive...
You'll eat peanut butter the rest of your life.
Hybrid Mode
