Just choose your favorite headphones. What they plug into (Nexus 7 in this case) doesn't matter. You might want to look into Klipsch S3 which can be found on sale for $25 and offer a ton of bang for the buck. https://www.google.com/search?q=kli...874,d.cGE&fp=56268de8494357c&biw=1200&bih=963
What is your budget? Preferred style (full size, on ear, ear buds, in ear phones)? What's important (detail, flat sound, big soundstage, "fun sound")? Also no matter what don't expect top end sound from the nexus. The audio guts are pretty weak Beats Me: Why HTC's "Amazing Sound" On The International One X Isn't Amazing At All - Even By The Numbers
If your budget can stretch just a bit I'd suggest the Sony MDR-V6 ($70) Bulletproof construction, very comfortable, and great sound at its price. Bass is the antithesis of Beats by Dre. Instead of huge booming muddy one note bass, you get just the right amount of fast controlled bass. These are a very immersive headphone with just about everything, especially when properly equalized. But they can be ruthless with low bitrate mp3, especially rock tracks with a lot of cymbal work. I also hear good things about the Panasonic RP-HTF600 ($30). These are cheaper, seem to have a lot more bass (which is good with action movies and most mainstream music) and are going to be more forgiving to those couple of 128kbps songs we all have. Personally the next full size cans I'll be buying are those Panasonic or the Superlux HD668B ($40-50). These will have less bass but a lot more detail and an overall larger soundstage. As with the sonys, don't expect them to play nice with low quality recordings. These also have a very flat frequency response. I like that, but you will probably want a good equalizer app to get the right sound for you out of them
