I wasn't around yet to witness this first-hand, but I will tell you I've actually owned reel tapes of Michael Jackson's "Thriller" (released Nov. '82) and Paul Simon's "Greatest Hits, Etc." (released Nov. 1977). So the end in stores must have been some time in between. Wikipedia (which actually reliable sometimes!) says reels were available through Columbia House until 1984, but usually only a very popular selection. So maybe look for "Born In the USA" or Culture Club as the end via mail order from a major label. Barclay-Crocker (makers of the high-end classical tapes) ceased in 1986. In-stores, though, I'm not sure. I feel like I saw a Crazy Eddie commercial from 1980 on YouTube, and you can still see pre-recorded reel tapes in the background.