What "Essential" DC Fighting Games Do I Not Own?

As much as anyone can actually "finish" collecting games for the Dreamcast, I've decided I want to "finish off" my Dreamcast fighting game collection by purchasing five more games.

I've decided on this number because I currently have 11 fighting game discs in my binder (I try to collect games complete when I can, but the fact is, I really like staring at a binder full of discs more than I like staring at all of my cases on my shelf), and 16 would allow me to fill two pages up with fighting games, turn the page, and have two more pages filled with fighting games. This appeals to me, for some reason.

Anyway, I have the following fighters:
Soul Calibur
MvC 2
Street Fighter Alpha 3
Third Strike
KoF 99: Dream Match
Tech Romancer
Spawn
Virtual On
DOA 2
JoJo
PowerStone

I've been considering:
Guilty Gear X
Vampire Chronicles
Psychic Force 2012
Capcom Vs. SNK 2
Last Blade 2
Mark of the Wolves
Fighting Vipers 2

Which five of these (or any others) do I "need" if I want to have the full Dreamcast fighting game experience? I'm pretty much open to any suggestions.

Oh, I use a Total Control/Saturn Virua Stick setup, if that is a consideration.