I've come around to sorta liking Making Plans for Nigel, but unless someone is already a big punk fan, I think it's a terrible song to give to someone who has never heard XTC. I would have ran the other way if I had heard that one first.
To me, you cannot go wrong with Black Sea, English Settlement (which could have lost a song or two in the middle), Apple Venus and the two Dukes records.
And while I wouldn't recommend it to someone new, I've really come around on The Big Express. It's dirty...it's grimy...it's really good.