Not sure what you like but the three Castlevania games for the DS are great. Not Symphony of the Night great but great none the less. Also, if you buy one and want to play SNES games on virtual console, make sure you get the New 3DS. The older one can't play them. They've released some really good ones so far. I've bought Super Metriod, Zelda: A Link to the Past and Super Mario World so far and I'm having a blast. There's also Earthbound to consider if you like RPG's.
I picked a "New" 3ds yesterday with Xenoblade, Zelda Link to the past, Dragon Age XI on DS, Dragon Age IX on DS and Final Fantasy XII Revenant Wings on DS. I have a long list of games I want (not all RPG's lol) but Earthbound, Super Punch Out and Mario World will be 3 Virtual Conole Games I will get. Loving it so far - are there trophies/achievements on 3DS games?
It depends on the game. The only one I have that has achievements is Retro City Rampage. There isn't anything like Gamecenter that keeps track of all your achievements though.
Ok fair enough. That's actually probably a good thing. I found that sometimes I would get so hung up on the trophies that I neglected the game. I.e. I would not play a psp game on the vita as there were no trophies. It's weird but I am glad so I can appreciate the back catalogue more.
Shantae and the Pirate's Curse to get a physical release in US and Europe http://www.risingstargames.com/eu/boxing-the-acclaimed-platform-adventure-shantae-and-the-pirates-curse/
There aren't many New 3DS exclusive games. All of the SNES virtual console games require the New 3DS along with the following list: Futuridium EP Deluxe Lifespeed Mini Mario and Friends amiibo Challenge The Binding of Isaac Rebirth Wind Up Knight 2 Xenoblade Chronicles 3D Runbow forma.8 For retail games, unless the game case says New 3DS, it should work.