What exactly is worth playing in that list?
Removing fluff, these:
Soul Sacrifice
Gravity Rush
Street Fighter X Tekken
Guilty Gear Accent XX Core + R
Silent Hill Book of Memories
Touch My Katamari
Metal Gear Solid HD Collection
New Little Kings Story
Dead or Alive 5 Plus
Ultimate Marvel vs Capcom 3
Super Monkey Ball
Soul Sacrifice isn't my bag and neither is Touch My Katamari but there's a market and interest in those for the system. GG doesn't have online so it's mostly a pass unless you are playing arcade/practicing for the console versions, so that's another pass but "worth playing." The others are ports of fighters/console titles that you may already own but that's the story of the systems life so let's ignore that.
They're not bad titles and I'm sure you'll scoff and demi is gonna demi but to dismiss all of them is just

If Marvel 3 was cross-play, which really is the biggest crime Capcom did with the port, it would easily justify my Vita purchase. Too bad it isn't to where the online is dead unless this sale brings a lot more people in.