Well, the worst trip experience for me had to be getting stuck in the storm of the century, back in 93, I believe. It was college spring break, and on the return from Florida, got stuck on the freeway in Alabama in a blizzard. My friends and I actually had to get out and push my car (small honda) along the road at points, till we could finally exit and get to a holiday inn. We were then stuck there for 3 days. The folks in Alabama kept saying - we know what snow plows are, we just don't have any. Luckily we made the best of the situation, and even got to participate in a wedding of a local family who couldn't get to a church in the country (one friend played the piano, and another sang). I now appreciate not ever having to drive in snow and ice conditions on a regular basis, and hope to keep it that way
Otherwise, I guess I have been pretty lucky in the travel department, on ground and in the air.