>>56532 (OP)metroid samus returns
Terraria
mario kart DS and 7
Get TwilightMenu++, you can play any DS game there. The advance wars games are great, the DS PVZ port, theres some CS1.6 port too thats fun to mess with.
Super Haxagon is autistic fun
if you use the new super ultimate injector you can get GBA games running well on the early 3ds models, play the GBA metroid and advance wars games
if youve modded it theres some movies you can play on the 3ds if you care about that
theres plenty of games, use hShop if you don't know about it already and download everything, get an SD card of at least 32GB but I'd recommend 64, it will fill up. You can copy all the files on your current SD card onto it and use it without any trouble.