You'll want one with microphone input jack. I can state with authority that the dozen or so units with builtin mics all gave results that your post's requirements would fail.
With the mic-in jack you can fit a microphone appropriate to the task or environment and get a good recording.
hi, i'm looking for a good portable mp3 recorder, playback & transferable to computer(don't need any mic external add-ons) that picks up good sound quality, to be used in lecture halls, auditoriums, minor feedback noise. does anyone know any good ones in the market? sony, samsung, other brands? thanks!