mmporsche---Welcome to the wonderful world of LP's! They often provide a completely different musical experience than a CD, or any other digital format. As his postings here testify to, Bill Hart (whart) is one of Audiogon's most valuable sources of musical recommendations in regard to both music and the sound quality of it's recording, particularly as available on LP.
Having already gone through the journey you are now embarking on, allow me to suggest that you focus on the music first, with superior sound quality, when available, as a welcome bonus. The sound quality of direct-to-disc LP's (recordings made directly onto an LP "mother", bypassing an electronic recorder of any kind) are uniformly far superior sonically to that of LP's containing a recording made via any electronic recorder. However, the music found on D2D albums, while sounding startling "alive", is, generally speaking, of little musical interest or value. D2D LP's are a valuable tool for ascertaining the quality of hi-fi components, but generally contain of little of musical interest.
Of the LP's notable for containing great music and great sound, Cat Stevens "Tea For The Tillerman" ranks among the very best. A really, really great recoding of music a lot of people like (particularly girls, I have discovered ;-). For details of the album's various pressings, see Michael Fremer's coverage of the album in both Stereophile and his own website. In fact, Fremer's writings should be your number one source for all things LP related.
"Song Cycle" by Van Dyke Parks (Brian Wilson's lyricist collaborator in 1966-7) is a remarkable album of music and lyrics by a very eccentric and brilliant guy. "Donovan's Colors" from the album was a cut included an LP that JBL put out in the early 70's, specifically to use as a loudspeaker evaluation tool. The harpsichord contained in the song is a brutal test of loudspeaker capabilities.
"Me & Bobby McKee" on Gordon Lightfoot's If You Can Read My Mind album is a great recording, not only in sound quality, but in terms of the song's performance by Gordon. I was present when the song was played for Bill Johnson of ARC by Walter Davies in 1972, at Walter's new Livermore California hi-fi shop. Walter is now the man behind the LAST line of LP care products, but in 1972 had just opened Audio Arts. On the day I first visited the shop, Bill was installing a complete ARC system. Walter played the song, and Bill was impressed enough with the sound to say "That is a great recording, what is it?". Walter gave him the LP, and I got myself one. Still have it!