Which Prince albums are worth owning?

There are some obvious ones: 1999, Purple Rain, 3121, the symbol album where he changed his name to an unpronounceable glyph. But he has a very large “oeuvre” and I know some of his albums are just stinkers, especially when he was pouting about his Warner Bros. contract.
Prince haters: Do not snarkily respond: “none!” to this question. If U R blind 2 The Purple One’s genius, please go elsewhere.