For the full-on absolute beginner, I would start with the greatest hits, HUMAN AMUSEMENTS. If you don't know if you'll go further than that, the hits are the way to go.
If you want to start with a proper album, you could always give BEE THOUSAND first crack at things. It's got enough hits dropped throughout that you'll find anchors to latch onto between the more 'difficult' songs (I'm not sure how good you are with the lo-fi stuff).
I got my start on PROPELLER, bought directly from the band (and sold and never re-purchased. Don't make me talk about it.) And upon looking at the track listing on it again from a prospective first-timers' POV, I am now saying START WITH PROPELLER.
Then you can always swing to BEE THOUSAND/ALIEN LANES/UNDER THE BUSHES, etc. Everything MAG EARWHIG on is more 'pro', for lack of a better term. It's all great though - you can't go wrong with ANY of it.
As for solo stuff, I have always been partial to KID MARINE, which is like Bob's version of a Who album in relative miniature, or FROM A COMPOUND EYE, which is a lot to digest at once. Maybe go with NOT IN MY AIRFORCE, which is kinda up the middle of the two poles.
If you need more, let me know. And anyone who has a contrary opinion, let's figure this thing out!
Tom.