My favorite period is 2007- 2010. I think this is CAVE's absolute peak output in terms of quality.
You have:
Muchi Muchi Pork!
Deathsmiles
Mushihimesama Futari Black Label
Dodonpachi Daifukkatsu Ver 1.5
Deathsmiles Mega Black Label
Deathsmiles II
Dodonpachi Daifukkatsu Black Label
Akai Katana
That's such a killer line-up! There's also nice parity with four horis and four verts.
What say you?