So far I have: rRootage online - classic bullet hell, lots of fun for practice although not anything I play every day buster red - I'm LOVING this. the cartoony graphics and satisfying gameplay/unlockable ships makes for a good game and it doesn't really get hard until the end of the campaign when it starts to get insane Icarus-X - kinda cool, nothing grabbed me though ESPGaluda II - never bought it because of the $9 price point, but I bought Dodonpachi Resurrection to make up for it. I also have iFighter but it's not really anything to write home about what am I missing?
Assualt squadron - my favorite Super laser - the alien figther Air attack they are in order from best to less. likewise on espgaladua . the lite was amazing but the price is holding me back
I honestly thought cave would put espgaluda on sale to celebrate release of dodonpachi. I bet if they did they would sell loads of copies, the number of people I see who want it but don't like the price.
R-Type was just released, and it's quite great. But yeah, Space Invaders is the most stylish and best in my opinion. Assault Squadron is a great bullet Hell type, and Warblade is a great Galaga-type. I also love Tyrian, but the full was pulled...still you can get the lite which has tons of gameplay anyway, and probably more levels than most of these other games like the ones from Cave or Assault Squadron do, even in their full versions.
I just bougt Ultrablast and it surprised me as a great schmup and also has bosses with bullet hell fight. Great graphics, smooth controls. Also you can have Armalyte through the C64 emulator, controls have been tweaked for better but it is still really hard play, for me at least. I assume you already have Tyrian, right? Ups, didn't know it was pulled out, well the lite it is still there, right? Galaga remix is a classic one too. The other one I enjoy a lot is Super Laser, a nice schmup