Any good shoot 'em up games?

[Slug-Gunner]

I'm an arcade gamer, I like to play Metal Slug, Raiden, Ikaruga, Geometry Wars, Chaos Field, In the Hunt, Silpheed, U.N Squadron, Gunbird, Contra, Gunstar Heroes, etc. I'm aware of Mushihinema but the game is freaking expensive on ebay, so no way in hell am I going to buy a PS2 game for over $100

I've also never played Defender, Life Force and Gradius so I want to know how those games are.

I want to know if there are more games like these, because I like a good challenge!

Oh yea, R-Type sucks, no freaking check-points make me feel like I'm playing Silver Surfer for NES and I hate that game too. Theoretically, its like you have to beat the game without losing a single time. At least U.N Squadron has a health bar.

[VGmasters]

Radiant Silvergun is supposed to come out later this year, pretty excited about that.

[SweetenBoy]

Youve probably already listed it.... Raiden 4. Just got it yesterday and can't put it down. SO EPIC

[KillerGoose]

Jet Force Gemini.

I'm not sure if this is a shoot-em up, but there's a whole hell of a-lota' shooting going on there. Quite an impressive game for it's time. Not only that, but the soundtrack is fucking awesome as well.