Grooviest Paul McCartney bass lines?

Might not be exactly what you mean but I’ve always liked Lady Madonna. And the bass is the main instrument through much of the song.

 

Everyone defines "groove" a little differently. That being said, I think that from his vast catalog of solo stuff, you'll find there's a lot of love (pun intended) among bass players for "Silly Love Songs" from Wings at the Speed of Sound (1976).

 

I Want You is pretty groovy. Also She Came In Through the Bathroom Window is sneakily groovy.

 

Maybe I'm Amazed

 

This for me. As a kid, before I even knew what a bass was, every time that song came on the radio I was mesmerized by that feel. Only later did I realize how it’s driven by the bass line.

 

Or preferably The Faces cover

 

I love Taxman

 

Dear Prudence has those wonderful slides up and down. Seems like it would be fun to play.

 

First one that comes to my mind, The bassline IS the song.

 

Lovely Rita. Seriously, give it a listen - your face will fall off. Who knew?

Another favorite, Something.

 

Silly Love Songs and Taxman came first to my mind.

After that, Some Other Guy.

 

Ditto on Something.

 

Not groovy in the sense you are probably intending, but I find 'Something' as one of the best Beatles bass lines:

 

Paperback Writer. Perhaps not groovy, but certainly busy, if not dominant throughout the tune.

 

I think The Word is and Drive My Car are pretty early indications he was listening to Jamerson (one possible thing that might =groove for you). There's lots of groovy on the White Album, esp. Everybody's Got Something to Hide and Why Don't We Do It In The Road.

Solo stuff there's so many things to check out, especially in the Wings era. He was particularly adept at making super simple root-5 parts sound groovy, like Listen to What The Man Said or Mrs. Vanderbilt etc. It's not easy to make parts like those have so much forward momentum, but he had a great feel for it.

He's still writing some top notch songs now and again, but I can't think of any especially groovy bass stuff from the 90s on.

(Also: A nuttier Beatles nut may correct me, but I believe George stepped in on bass for She Came In Through The Bathroom Window.)

 

And Your Bird Can Sing.

 

Check out Wings' Silly Love Songs. Definitly one of my favorite McCartney lines.

 

Lots of good suggestions here, but I'll throw in Hey Bulldog, a tragically under-rated Beatles rocker with a killer bass line.