I don't use a lot of the extensions mentioned in the 2 links wraith provided, but FWIW, I thought I'd mention the extensions (not plug-ins) I've currently got on Pale Moon, most of which I also had when I used Firefox:
Adblock Latitude (a Pale Moon version of Adblock)
Surfulater Integration (I'll probably remove this soon, since the developer is no longer working on Surfulater)
Tiny URL generator
Even if they no longer work on Firefox, they'll continue to do so on Pale Moon, though it may become harder to find some of them.