LogFAQs > #972259876

as far as virtual console stuff goes, I might as well mention some of the stuff that has changes to them or are otherwise notable:

3ds
Summer Carnival 92: Recca - it's basically a tech demo that was made for a game show, so it never got a wide release. It was fairly influential to the shmup genre and worth checking out if you're a fan.
Pokemon Crystal - I believe they modified the game so that you're able to get Celebi.

Wii U
Super Mario Advance 4: Super Mario 3 - modified to include all the e-reader levels (although it's on the NSO app now)
Mega Man Battle Network series - modified so that you don't have to link to another cartridge for certain completion stars (though there's probably not much point in getting these releases over the upcoming legacy collection)
Animal Crossing Wild World - modified so you don't have to trade or use wifi or w/e to unlock certain things (although there's probably not much point in playing this particular version over other ones)
Fire Emblem Shadow Dragon - modified so that the wifi shop is available without wifi

The Wii U also has some Turbografx 16 games, which can be easy to overlook since there isn't a separate category for them on the eshop home page. a brief overview of some titles since it's a system fewer people are familiar with

Alien Crush, Devil's Crush - fun pinball games (if you had to choose between them, I'd say go with Devil's Crush)
New Adventure Island - it's a lot more accessible than the NES games (AI1 is a pretty good candidate for the hardest NES game after all), but it's a gameplay style that not many people would be into since it's a precision game with a lot of memorization/trial and error involved
Bonk series - failry standard platformer with some goofiness
Air Zonk - Bonk themed cute em up style shmup
Bomberman series - pretty standard Bomberman titles that don't reinvent the wheel (94 is probably a little better than 93 though)
Panic Bomber - Bomberman themed puzzle game, but I think it's bad
Battle Lode Runner - you have to know how to manipulate how the AI moves a bit, and it's a style of game that probably doesn't appeal to everyone
Lords of Thunder - fairly popular fantasy shmup with metal soundrack. Can pick your weapon type and stage order, and you can buy upgrades between levels.
Super Star Soldier, Blazing Lasers, Final Soldier, Soldier Blade - Compile shmups are solid and and accessible for even people who aren't very good at the genre, although they're all fairly similar to one another (so if you only get one I'd say get Soldier Blade, or maybe Blazing Lasers)
Chew Man Fu - maze arcade game where the goal is to push balls onto matching pressure plates, and you can use the balls to run over enemies or break down walls
Neutopia - Zelda 1 clone
Dungeon Explorer - Gauntlet clone I guess?
Necromancer - mostly just mentioning it to say don't buy it, it's an rpg and it's not translated

There's also some ports of Gradius and Salamander/Life Force that have some differences from other versions, but the differences probably don't mean a whole lot for non fans and I don't think they have Gradius 2 on there which would be the one of them that I would suggest if you only wanted to play one.

A lot of the same games are on the Turbografx Mini (and some ones that aren't), if you're interested in one. Though there's also some on the eshop that aren't on the Mini (Bonk 3, Battle Lode Runner, Final Soldier). If you're only interested in buying a couple Turbografx titles, I'd say the best overall ones to consider would be Soldier Blade, Lords of Thunder, and Devil's Crush.