Trespass - One of These Days.
Some old 80's Brit Metal band I'd never even heard of til I got this audition comin' up Tues.It really is a butt-simple line, but it really does drive the song.
Flight of Icarus by Iron Maiden seems to meet the criteria too. It's pretty much all about right hand technique, timing, and riding that F note for the most part.... There's nothing more complicated to it than a few 5ths, octave climbs, and slides, but it really does drive that song too. (It's funny how when you ride that F so long, it makes that part where it dips down to the open E seem so much deeper/lower.)
Message in a Bottle by The Police is another fine example of a fairly simplistic line, yet it's the entire backbone of the song.