A good mix of both. For my PSP, I jumped from physical to digital and never looked back. I even re-purchased some games I owned physical copies of.
For the PSVita and 3DS, I prefer physical because the games are small enough to carry without damaging them and they aren't on disc so there is no performance upgrade for having them on the memory card.
With my home consoles, I prefer physical for every retail game. I install everything I play on the 360, btw. I even bought the retail version of Super Luigi because I needs my discs! Plus Nintendo are assholes when it comes to DRM. The exception are the bite sized games. If it's a Virtual Console title, XBLA game, PSN game, indie game, or whatever, I rather have them on the HDD (and I usually have no choice anyway) because they're pretty short and I like browsing through my collection searching for something to play.
Never gonna download a retail PS3, Xbone, or PS4 title because they're too damn big. The exceptions (and they've been for Wii U and Xbox) are when there's a huge sale and the game is small.
