Favorite "uncomplicated" basslines.
 

I'll start this off by mentioning "Maneater" by Hall & Oates. T Bone Wolk's bassline is simplicity itself, but it literally IS the song. Next?

I love the bass line of most Jimi Hendrix songs, but especially Third Stone From the Sun and Fire.

"Date With IKEA" by Pavement. Pretty much just arpegiated power chords with a tone so lo-fi and trebly it almost sounds like some sort of synth-bell.

"The Autopsy Garland"--the Mountain Goats. Mostly empty space, with some perfectly timed and ever-surprising dissonant stabs (like a scarier "Airbag", almost).

"Dogs Were Barking"-- Gogol Bordello. Simple and ridiculously danceable breakdown ("now dub it tovarisch, like tovarisch would...").

OMG Midfour, did you pick the most obscure music on this planet or what? J/K

My vote: Queen's "Another One Bites the Dust"

"Talking In Your Sleep" by The Romantics. Another bassline that carries a tune.

Roxanne -The Police
The Beatles- When I'm Sixty-Four

I've always thought P-Nuts line in Amber was the epitome of "less is more". It is a pretty simple line, but it grooves hard.

Tom Sawyer - Rush

Green Eyed Lady by Sugarloaf. If you've never heard it, check it out. You'll understand why.

P-Nut was/is a HUGE influence on my playing (just look at my screen name :) ) As to the OP, Last Night a DJ Saved My Life by Indeep and Hot N Fun by NERD. Simple and funkay!

Petits Machins from Miles Davis' Files de Kilimanjaro.

Inner City Blues - Marvin Gaye
Nobody Knows - Band of Gypsys
Hey Joe - Hendrix
Stir It Up - Marley
Lo Rider - War

Back In Black by AC/DC. I have heard more otherwise killer bassists expose themselves as weak in the feel department over that one.

I'm a FUNK guy so:

Are you Single by Aurra
Glide by Pleasure

and I'll add another since he seems to be in the news. Sexy Dancer by Prince. So simple but so damn effective.

If you haven't already, check out Andrew Levy with the Brand New Heavies (poetry unintended). He doesn't do anything too flashy, but he grooves so deep.

It might be safe to say, paradoxically, that "simple" is actually more challenging. Some can vomit all over a song with complex lines, but to hold the line takes self-control. Some of these lines in the post are sometimes difficult to play, well.
My vote is "Keep Looking" by Sade
Paul S. Denman is a machine.

Chameleon is awesome and pretty simple yet grooving line. Best under the influence song ever.

As far as simple lines go lately I've really been digging "public witness program" by fugazi and "brand new Cadillac" by the clash.

I don't know that song, but everything Gogol Bordello is awesome, so I'll give it a shot.

Echoes by Pink Floyd.

(Take that, Roger haters!)