Not sure which lossy format to use for Android playback Options

[Cromulent]

My music collection is currently encoded in FLAC format and was ripped using cdparanoia. I want to convert some of my FLAC files to a lossy format for listening on my Android phone at work (Nexus 4 for reference) but am unsure which codec to use. I think the choice is really between AAC and Ogg Vorbis but I'm not really sure. I'm basically looking for the best sound quality with the smallest file size.

Can anyone offer some advice for a newbie in this field (prior to this I've only ever really used lossless formats such as ALAC or FLAC).? Thanks.

[Seren]

I use Opus with Rockbox on my my Phone (running 2.3), Rockbox is in development still for android but it's extremely useful. There are other players on Andriod that play Opus and are more stable but mostly require 4+.
If your one who likes to use the integrated player then you'll most likely want to use AAC (using QAAC).

EDIT: I was using Vorbis before Opus, since I've never really been a fan of low-bitrate AAC, although many listening tests show people prefer AAC over Vorbis.

This post has been edited by Seren: Dec 6 2012, 17:26

[DonP]

There are other players on Andriod that play Opus and are more stable but mostly require 4+.

The OP's phone would have android 4.2