It really boils down to your general genre preference. For example, the types of games I like my brothers don't and vice versa.
My Top 5 recommendations based on my preferences:
1.Rune Factory 4: it is a must! It has so, so much content packed in one game and no DLC needed to access it. Great story, beautiful music, lots of fun dialogue and so much to do. It's like a mixture of Animal Crossing, Final Fantasy and a hint of Pokemon. To me it's the best game on the 3DS
2. Fire Emblem Awakening: Great story and lots of fun to play. To me it's the best Fire Emblem game to start off with besides 7
3. Bravely Default: Made by Square Enix should be 'nuff said. Story is good, gameplay is fun and the music is chef kiss.
4. Kid Icarus Uprising: Just trust me on this. It's good!
5. Denpamen 2 it's an Eshop game only,
but it's like a bit like Pokemon Go, but better IMO. It has unique Denpa men, depending on your location and really funny dialogue.