i can't help mentioning tom waits the early years vol. 2 (occasionally off-key, out of time, skipped notes: near sublime!) and Steve Forbert (especially his first LP 'alive on arrival' - not all are just acoustic only but some are and the songwriting is some of the best there is) and tracy chapman of course (first effort), chris smither "live as I'll ever be" (great song writing as well), of course neil young and CSNY various and cat power! oh yeah, duh. various dead.
thanks for reading. comments on these suggestions much appreciated.