Well, lots of stuff from way back in the day I'm not too clear on, but a few faves that spring to mind right now:

Delaney & Bonnie's "Come on in My Kitchen" (later ripped off by the Dead--and I mean ripped off affectionately)

The entire Jeff Beck catalog! You know, "Morning Dew" etc etc

Yes, I loved the Beach Boys version of "Sloop John B" because they made it sound so hippy dippy!

The Everly Bros "Songs Our Daddy Taught Us" completely charmed me when I discovered it at the time of Rhino re-release.

The Band/Burritos/Byrds were faves of mine, but there isn't any of their covers of trad tunes that stand out for me. Maybe "Night they Drove Ole Dixie Down". I preferred Nitty Gritty Dirt Band for the rocked up trad versions they did.

Being a big rockabilly fan, I also loved the older rockers like Carl Perkins and Gene Vincent (god I loved Gene Vincent!). More recently, it's been the revivalists extraordinaire: Stray Cats. Sheer joy.

Pentangle and Steeleye more than Fairport for me. Planxty, Moving Hearts, Paul Brady, Davy Spillane.

Bonnie Raitt's live duet with Sippie Wallace "Woman Be Wise" on her greatest hits CD. Lots of Bonnie's country blues stuff.