I like buying the physical copy most of the time, but for sand-box &/or life simulator kind of games, I find more convenient the digital download so it is always readily available. That and Zelda games. I think there are still obstacles to make the digital more convenient over retail. Right now there is the fear that if your 3ds breaks you lose your games I really want to think that since the game purchase get linked with your club Nintendo that is not the case) and also usually Nintendo consoles have retro-compatibility. With physical copies if you upgrade you most likely will still be able to play those physical 3DS titles.
Now, for me so far this is my physical games collection:
- Super street Fighter IV 3D edition
- Rayman 3D
Those above are the ones I own. Yeah, I was expecting to type more titles too.
Thanks to my room mate I can have a taste of more titles that we both enjoy, maybe at some point I'll get my own copies for some of them. My roommate is the main force behind our game purchases.