Best 128k AAC codec, quicktime.
Describe your problem more detailed so we can help you.
MPC, AAC, Ogg Vorbis, and MP3 can all be the best depending on what you need.
MP3 is not needed for anything but compatibility. If all portable players now supported Ogg Vorbis and/or MPC and AAC, MP3 would have no use.
MPC is the best at 160k, no doubt, qualitywise. But it has no chance of getting hardware support as I see so far.
Ogg Vorbis has chance of getting hardware support. iRiver is on it, the Neuros already has it(well, somewhat, above 200k it's fux0red

). It's still better than MP3, even at high bitrates from my experience; all the posts of MP3 being better at high bitrates confuse me, it's the exact opposite for me, and many others.
AAC, I'm not that familiar with since I've never had a use for it, or a cause to use it, so I don't know. I know it's nowhere near as good as MPC at 160k+. Ogg Vorbis GT3 and AAC are like apples and oranges at that bitrate, I'm not really sure, I haven't tested it for myself, that's just what I've picked up here so far.
Hope this helps.