Sparks' 80s albums after AIMP are horrid, though I love "Love-O-Rama" a lot for some peculiar reason.
Steely Dan - They were always at least adequate, but their first two are the best by a slightly signficant margin, IMO. I'm going with Countdown To Ecstasy (a commercial flop that also saw the band quit performing live; the liner notes to the reissue are a laugh riot) as the masterpiece. "Bad Sneakers" is their best tune though, what a total 70s song that thing is.
I felt that Gaucho verged on elevator music and I haven't heard their two reunion albums.
If you like them, please hear Donald Fagen's The Nightfly (1982) and Kamakiriad (1993), off the top of my head the latter had Becker helping out a lot anyway. They're totally out of their times, but they're good! The second is a FUTURISTIC CONCEPT ALBUM!