I'm not sure if they will all of these are $20, but none of them should be over $30.
Injustice - A DC Comics fighting games from the makers of Mortal Kombat 2011 and MKX. The online community is probably dead by now, but I enjoyed this one more than some other fighters. As made obvious by the Teen rating, this is not Mortal Kombat: DC Edition. The game has a diverse group of 24 fighters, both heroes and villains. One fun aspect is that each character has a button tied to their unique abilities. FWonder Woman can switch between her Whip and Sword for different moves, Lex Luthor creates a force field, Green Arrow gets a number of weaker ranged attacks, etc.
Monster Hunter 3 Ultimate - The original Wii game was huge and amazing, but the Wii U version is the definitive one. You get you Monster Hunter Tri, throw in HD, better online multiplayer, cross-compatibility with the 3DS version, and the GamePad for menus and HUD in addition to basic new content. This is a series of big meaty Action RPG's, and this is probably the best in the series on consoles thus far.
Nintendo Land - A former bundled game, this is quite cheap to get used nowadays, maybe $10. Think of it kind of like Wii Play in how it shows off the GamePad, only with more substance. Out of the 12 minigames, some are better than others, but the three "Team Attractions," which can be played alone or with others, are worth the $10 by themselves. The Zelda-themed action game lets you use either the GamePad as a bow or the Wiimote as a sword to beat waves of baddies. "Pikmin Adventure" is sort of a simplified combat-oriented imagining of the series where friends can play as Pikmin. Metroid Blast is my favorite: a third-person shooter where the GamePad can be used to pilot Samus's ship. All three have proper campaigns to play through. The remaining nine minigames are less substantial, but this is well worth $10.
Resident Evil: Revelations - Originally a 3DS game, Revelations was ported to consoles because it was the best Resident Evil title Capcom had made in a while. The game tries to compromise between the past roots of the series and the new action elements. It doesn't always succeed, but does far better than RE5 or RE6. Note that in addition to the main story, there is an action-oriented Raid Mode that complements the action orientation of the series. Just remember that even with the HD makeover, this game started on a handheld, and thus won't graphically dazzle you.
Warriors Orochi 3 Hyper - Big action game where you slaughter thousnads of enemies as one of over 100 playable characters. As a launch title, it suffers from performance issues, but might be worth a look.
Wonderful 101 - Platinum Games, in between releasing Metal Gear Rising and Bayonetta 2, released this quirky action game back in summer 2013. It lives up to their reputation. You play as a team of cheesy superheroes fighting off an alien invasion. Things become increasingly epic and silly from there. Has some incredible boss fights.
ZombiU - You mentioned you were getting this, but I felt it warranted another mention.
Love and tolerate.
