I recommend the iRiver iHP-120. You can record to MP3 or WAV from the internal mic, external mic, or line level input. Mine is 20 GB. Shows up on my WinXP machine as an external harddrive (USB connection). Some limitations: No level meters while recording, no timestamps on the recorded files, no on-board delete functionality. Works great for field recordings, recording live performances, etc.
well i've got thie ihp-140 ... nice mp3 player ... but i recorded a concert directly from my hdsp's analog output ... the sound quality wasn't that good, though ... but it has a digital input so if you have an external adc, it's probably much better (haven't tried it)
cheers ... tim