160/atrac3+ on sony nw-a1200. i used to use 256 but ive come to realize when i'm on the go it doesn't really make much difference so i opted for longer battery life. 128 is actually fine for some songs but for consistency and ease of transfer i just stick to one rate.
MP3 Lame, constant bitrate of 320kbps on my Sony NWZA829, but may consider dropping quality of rips to 256kbps or one lower even to accomodate more music on my 16GB DAP in future.
I also rip all my CD's to .FLAC, before converting to import to DAP.