A couple more thoughts:
For sound quality, you may want to look for the Mitchell Froom productions.
These aren't necessarily "audiophile" recordings, but they are
generally good recordings of vocal/guitar surrounded by lots of stuff that
"enhances" the main ingredients. Unfortunately, this was a
relatively brief period (see "Action Packed", a Capitol Records
greatest hits collection) where RT made very good music, but it misses much
of the variety that makes his catalog so wonderful.
Also, RT is, as much as almost anyone I can think of, all about live
performance. His website offers many live cds, any of which will be
worthwhile. My personal favorite is "Two Letter Words" and I'd
highly recommend it.
Finally, listen carefully to some of the lyrics on those early records. Songs like
"Dimming of The Day" and "Walking on A Wire";("Where's the justice, where's
the sense, when all the pain's on my side of the fence?") . Then check out
the more recent stuff like "Guns Are The Tongues" , "I Feel So Good" ,
"Waltzing's For Dreamers" , etc. You really get a sense of just how broad RT's
lyrical ability is.
Marty