i listened to them a lot in college, but never religiously or anything. been getting back into them recently.
over at archive.org you can download all kinds of shows for free. lots of good soundboard recordings, many available in flac.
this one is particularly nice, with 25 wonderful minutes of Scarlet Begonias/Fire on the Mountain
Internet Archive: Free Download: Grateful Dead Live at Barton Hall - Cornell University on 1977-05-08