their last one was a weird Plant and Jones project

In Through the Out Door is killer! Sure, "All My Love" and "Fool in the Rain" are not as hard as some earlier stuff, but they're excellent songs. "I'm Gonna Crawl" and "In the Evening" are "pretty good" by Zeppelin standards, which translates to "outstanding" by normal band standards. Then you got "Carouselambra", a tour-de-force to show you that they've still got surprises -- there are people out there whose lives were changed by that song. Admittedly, "South Bound Saurez" and "Hot Dog" are mid, but those add up to like 7 minutes on a 42-minute album.

Anyway, that was why Led Zeppelin was so amazing. They had so much talent that even when half the band was out of commission on drugs, they still put out a first-rate album.