I'm going to assume that you already have a Wii U in first place. There are games that you don't get from Wii U eShop, as they aren't available yet as of January 17th 2015.
Chrono Trigger (SNES) is one of the most phenomenal JRPGs of the 90s. The new battle system livens up a lot of the standard JRPG fare, expressive character design is done by the famous Akira Toriyama, and the production values are great for a SNES title. You'd definitely want to check this one out.
Love running and gunning, but don't like dying too fast a la Contra? I'd recommend you trying out Gunstar Heroes (Genesis/Mega Drive). It's a fun, fast-paced game that stands the test of the time. If you're feeling particularly brave, try the Expert difficulty and see if you can beat this one.
Craving for some more platforming that isn't just from Nintendo? You can't go wrong with any of the main Sonic game from the Genesis/Mega Drive. If you purchase Sonic & Knuckles along with Sonic the Hedgehog 3, you'll be in for a meatier game.
Ogre Battle 64: Person of Lordly Caliber is a fantastic SRPG only found in Nintendo 64, and it's even on the Wii Shop Channel. You get around 50 hours of gameplay, a well-explained tutorial that makes the game's complexity less overwhelming. Considering it's a rare game that would otherwise cost well over $90, the Virtual Console version of it is far more accessible than getting the original cartridge.