Almost EVERY cast album produced by Goddard Lebersion from SOUTH PACIFIC thru A CHORUS LINE. Notably THE MOST HAPPY FELLA, issued on 3 LP records complete with all the dialogue.
Sheppard's SWEENEY TODD and SUNDAY IN THE PARK original Broadway cast albums were technical marvels in their day.
RCA Victor's late productions under Bill Rosenfield were excellent: RAGTIME, STEEL PIER, PARADE. I would include TITANIC except for the maddening low lovel across the disc.
All of these give you a real sense of the show.
Disney's LION KING is an example of a poorly produced cast album. You get the music all right but no sense of the show. And somehow RENT doesn't come through nearly as well on CD as it does in the theatre.
I have been most impressed with the new COMPANY.
Cast albums are NOT "soundtracks."
Live theatre does not use a "soundtrack." If it did, it wouldn't be live theatre!
I host a weekly one-hour radio program featuring cast album selections as well as songs by cabaret, jazz and theatre artists. The program, FRONT ROW CENTRE is heard Sundays 9 to 10 am and also Saturdays from 8 to 9 am (eastern times) on www.proudfm.com