I must admit I like Fables of the Reconstruction, it being the first REM album I came across, but I agree I'd probably not recommend it as a starting point to a recent convert. In this respect I'd have to go with my esteemed colleagues that "Automatic for the People" and "Green" would be the studio albums to start with, but for a true novice I'd go with two compilations:
1. "In View- The Best of R.E.M. 1988-2003" (covers the Warner years)
2. For the EMI years there is little to choose between the two compilations "The Best of REM" or "Eponymous", the differences being (IMO) not the better tracks.
The good news is that the albums are all really cheap on Amazon!
http://www.amazon.co.UK/exec/obidos/ASIN/B0000CC6QF/quid=1122217628/Sr=2-1/ref=Sr_2_11_1/026-8778146-4042043http://www.amazon.co.UK/exec/obidos/ASIN/B0000073AK/quid=1122217212/Sr=1-5/ref=Sr_1_11_5/026-8778146-4042043http://www.amazon.co.UK/exec/obidos/ASIN/B000002UVY/quid=1122217397/Sr=1-20/ref=Sr_1_2_20/026-8778146-4042043