Lots of great versions of “All along the Watchtower” out there. Bob himself, Jimi, Bob with Tom Petty and the Heartbreakers are 3 of my favorites. Dave Matthews has a good live version.Can't really call this a "best" thread; more about covers you like.
Some covers try to stay faithful to the original, some repurpose the original and then you have straight up cover bands which cover all types of music.
I'll start off with one of each.
"I'm a Man" covered by Chicago. Original was by Spencer Davis Group.
My daughter saw Pink in Houston last week and said she did a killer "Smells like teen spirit".Joe Cocker "The Letter"
James Taylor "You've got a friend"
The Eagles "Take it Easy"
Aerosmith "Train Kept a Rollin"
Pink "Me and Bobby McGee"
I like Joe Cocker's cover of Screamin' Jay Hawkins' "I Put a Spell on You" better than the original, even though Hawkins was of "my" era, and I saw him do it live (at the State Theater in Hartford, some time in the late 50s.).
I don't think you can classify the Eagles' version of "Take it Easy" as a cover. It was co-written by Jackson Browne and Glenn Frey, then a fulltime member of the Eagles. Jackson Browne's version wasn't released until after the Eagles' version.Joe Cocker "The Letter"
James Taylor "You've got a friend"
The Eagles "Take it Easy"
Aerosmith "Train Kept a Rollin"
Pink "Me and Bobby McGee"
Not a big fan of organ music, so never got through the intro.<G>The Crazy world of Arthur Brown cover of the same song from 1968:
Arthur Brown - I put a spell on you