Truth is the one i still listen to the most, and a lot of that also has to do with Young Rod on vocals... Blow By Blow or Wired might be more impressive musically, but something about Truth just grabs me every time.
Blow by Blow was the first I heard, other than "Beck's Bolero" which was an actual AM radio hit of my youth. I liked it a bit better than Wired. I also got the "Truth" LP on a two-fer and didn't like it as much, but it's clearly from a different era and I wasn't expecting Rod Stewart.
I don't think I've ever fully listened to the "Jeff Beck Group" stuff he did just prior to Blow by Blow.
After that, Guitar Shop melted my face, Terry Bozzio being an important part of that experience. Glad I saw that tour (opening for SRV).
I got his 3 techno albums as well - those have their moments, but the production seems often to take center stage as Jeff's not known so much for his compositions.
Live at Ronnie Scott's is also pretty good. "Scatterbrain" off that one will straighten your curlies.
I listened to "There and Back" in the car recently and didn't really dig it all that much by comparison.
Man...how can you pick one? Such a rich career filled with so many highs!! I guess my personal favorite is Blow by Blow...though I really love so many of the records leading up to it and maybe even more after. Jeez, I can't think of any other rock guitar player who deserves more respect. He's never stopped to rest on his laurels.
I love plenty of other eras and songs, but...if I was going to say "what makes Jeff special", it would be those two. He needs strong collaborators and song writers to piece together songs that feature his awesome touch and phrasing.
I love Jeff Beck but admittedly don't know much of his catalog outside of the yardbirds and a few well known solo releases. IME, his best work was the mind blowing live performance he put on when i saw him in 1989 at MSG (w/ SRV on a double bill)
i like all the Beck albums that i have:
You Had it Coming
i also really like Flash, i know he's kind of written it off, but there is some great stuff on there. I still listen to it.
Used to have: Truth, Beck-ola, and There and Back, and liked them too!
Blow By Blow as an album is unbeatable for me, personally. The mix of moods/styles from song to song and the quality of the compositions are Beck's finest release, IMHO.
That being said, I listen very often to Truth, Wired, Beck's Guitar Shop, and Live at Ronnie Scott's. You just can't really go wrong with Jeff Beck. One of the most musically expressive electric guitarists; each note is a little living universe of musical expression via vibrato, bending, sliding, etc.