I love Twin Peaks--I saw it when it first came out, and I dressed like the Log Lady for Halloween one year. Haven't re-watched it in ages, though.
Eraserhead I didn't like as much, although it does certainly have some memorable images. (Pulsating chicken, anyone?) I love Lost Highway, Mullholland Drive, Blue Velvet, and Wild at Heart. I've never seen Dune, but I'm gonna go see it tomorrow--it's playing at a revival theatre near me.
I agree with what folks have said here--David Lynch films are often as cryptic and mysterious as dreams, and as with many dreams, impossible to interpret. With Lynch's films, I just like to sit back, and enjoy the ride.
I have never let my schooling interfere with my education.