ZZ had three big time albums in the 80's, which is the period covered in BTTF. I like them all myself. Here's a brief description:
Eliminator, 1983: Their breakout and "comeback" of sorts, which introduced their southern brand of pop/hard rock to the early MTV generation.
Hits: "Gimmie All Your Lovin," "Legs" (in a slightly remixed version at times), "Sharp Dressed Man," and the slightly retro-ish "Got Me Under Pressure."
Afterburner, 1985: Probably the most removed album of their career. Backing even further away from the blues and giving a very "80's pop-ish" hard rock album. Their sense of humor really shines through here.
Hits: "Stages", "Planet of Women" (synthesized party rockers), "Sleeping Bag" (80's rock with a blues tinge), "Rough Boy" (country-flavored rock ballad).
Recycler:, 1990: I'm less familar with this and haven't listened to it in awhile, but it showed the band slowly turning away from their 80's hits and back toward a more blues-based sound.
Hits: "Pearl Necklace," My Head's in Mississippi" (both reminiscent of their new blues sound), "Give it Up" (more 80's type pop/rock), "Doubleback" (needs no introduction :D ).
My vote: Although the biggest hits came off Eliminator, my overall favorite album is Afterburner, which I've had since 1995, when someone gave me a slightly used tape copy I still have. Even the non-hits are really good.