I finished like 30 games last year and I'm pretty sure more than half of those were from the 3ds, since I drew pixels of them.
It's my go-to system until I finish most of my backlog.
Currently I'm doing a Neutral run of SMTIV since I got the Law ending first, and then there's a bunch of games that I pick up in short bits (umihara kawase, wario ware, nes style boutique, theatrhythm final fantasy, super mystery dungeon, retro city rampage...)
After these, I'm not sure. I still have Fantasy Life, Etrian Odyssey 5, majora's mask 3d, senran kagura 2 and Project X Zone 2 unplayed or at the very beggining, and for SMT there's apocalypse and soul hackers as well.
I guess it'll depend on wether or not I'm in the mood for more SMT or not, since these games are so long.
Gotta clarify that I got a new3dsxl a couple years ago, so that's why I'm more than happy to keep playing it. Umihara Kawase hurt my hands badly on the original 3ds due to the dpad, but here it works great.
Edit:
Forgot to mention rhythm heaven, but I almost gave up on that one because of the door guardians. They singlehandly ruined for me what should have been one of the best entries in the franchise...