Capcom: Fei Long, Dee Jay, T.Hawk, anyone else from SFA3 they missed, and some from SF3: Third Strike.....and raid the Mega Man series.....
SNK: they need to get the Samurais in there...
Hattori Hanzo (special intro with Galford)
Galford (special intro with Hanzo)
Kazama Kazuki (special intro with Sogetsu)
Kazama Sogetsu (special intro with Kazuki)
Kibagami Genjuro (special intro with Haohmaru)
make Rimururu playable (special intro with Nakoruru)
Tachibana Ukyo
Amakusa
Zankuro (hidden character)
add those and I think it'd be set.
SNK: they need to get the Samurais in there...
Hattori Hanzo (special intro with Galford)
Galford (special intro with Hanzo)
Kazama Kazuki (special intro with Sogetsu)
Kazama Sogetsu (special intro with Kazuki)
Kibagami Genjuro (special intro with Haohmaru)
make Rimururu playable (special intro with Nakoruru)
Tachibana Ukyo
Amakusa
Zankuro (hidden character)
add those and I think it'd be set.