What digital camera including MP3, voice recording,... is best seller ?

Sony Cybershot DSC-N1 8.1 MegaPix Cyber-Shot Camera. I bought 2 of them last month 1 for my wife and 1 for my niece. They both love them. It's about $350.00 each.

As far as I know, there is no digital camera with those specs. You will need to buy a mobile (cell) phone for what you want.
Sony Ericsson has several models...with a camera, voice recording and MP3 etc.
Look at the...
Sony Ericsson W810i...2MP camera.
Sony Ericsson K800....3MP camera
Sony Ericsson K790....3MP camera
and Nokia has some models too I think