I think RV's discography is decent. It's definitely much better than some of the trash that SNSD were given in their earlier days.
The Red is a great album, I only deleted Day 1. On RR, the title track, Some Love and Lucky Girl are the trinity for me.
Their singles Happiness, Be Natural and mini album Ice Cream Cake are also great. I liked most of The Velvet, but some of the remixes were tragic.
I hated the whole RR mini on first listen, but it grew on me really quickly.