I recently got Seaside. One of the recommended kingdoms is the following:
I've played it twice; in the early game I would get Ghost Ship, Sea Hag, Warehouse and a Native Village or two. The sifting of Warehouse, the knowledge that I have a Curse on top thanks to Sea Hag, and a bit of luck means my NVs would set aside more or less only junk while I was busy attacking my opponent and buying the odd Silver.
Around the time the curses were out, I'd pick up Salvager, Treasury and Gold in some mix, trashing Sea Hag and using Salvager to turn my deck into Provinces.
The neat part is trashing NV with Salvager.
I figure that "If you trash your NVs, you have effectively trashed the cards on your mat" is not a novel idea.
The fact that you want to transition from a deck with a village or two to a deck with a bunch of money and a few Salvagers, right around the time where NV becomes less attractive to play (in either mode), is what makes the Salvager/NV interaction neat, and that feature is quite kingdom-specific.
I find it particularly neat that NV will happily "trash" cards that Salvager is sad to trash and vice versa—and NV will succeed at it with good probability. Also, Salvager is terminal which is fine in the end-game while NV is anti-terminal which is great in the early game.
The complementarity is strong with these ones.
(I think I opened 5/2 in both my games, which makes getting Ghost Ship rather easy; it probably plays out differently if I open Silver/Sea Hag.)