Starter motor (replaced twice) ; head gasket blew at 270,000 miles; power-steering system leaks; un-fixable oil-leak (from rear main seal).
Generally I love these cars...I've owned 27 VW buses (including 10 Vanagons). They've saved me thousands of dollars in Motel-fees I would have had to pay if not for the bed in the van. I like the way they handle, and the water-boxer has enough power for me.
A caution: do not add STP (or similar oil-treatment) to a full crankcase: I did and blew out the rear-main oil seal and had to drive on it for a couple days which resulted in damage to the block (I had the seal replaced, but it still leaks oil badly and this cannot be fixed except by an engine replacement).
I would add to this advice: do not use Fram or other aftermarket oil filters, only VW or Bosch brand. The aftermarket filters will allow your oil pressure to drop low enough to trigger the warning light (and buzzer, if equipped).