I didn't even think about the Dukes of Stratosphear stuff - I guess my brain puts it into a different category, probably for the same reason that they categorized it differently - but yes, the entire Chips From The Chocolate Fireball collection is among their best work as well.

To add in to the discussion about Nonsuch and Oranges & Lemons, well, I still think O&L is depressingly mediocre. "Mayor of Simpleton" is the only one on there I return to with any frequency. However, I just relistened to the pair a couple of days ago, and Nonsuch is much better than I remembered it being. For some reason, I always just lumped it in with its predecessor - I think a lot of people do that with those two albums, actually. But Nonsuch is a fantastic pop album that would be the best album many bands could hope for - XTC have so many great albums, it doesn't even crack their top 5, but that's a testament to how good they are rather than any weaknesses the album may have.