History of AIDS and Pleasure Ground probably had the biggest impact on me when I was first starting Concrete Mascara, in the sense that I wanted to make things sound like Pleasure Ground but they came out way closer to the blown-out, hyper aggressive insanity of History of AIDS. the track "Vertigo" from History of AIDS is my favorite Prurient track.
My other two favorites, which I honestly listen to the most often are The Baron's Chamber CD on Nihilist and the Time Began in a Garden 2xcassette. The Baron's Chamber is an extremely well executed mash-up of several live sets which basically combine the sounds and vibes of Troubled Sleep, Fossil and The History of AIDS into something dense and feverish. The repetitive bass-y synth ending that's like the last 7 minutes of the 30 minute track is just a giant fuck off while being ear candy at the same time.
As for Time Began in A Garden the combination of theme, packaging and sounds makes this the best of all mellower Prurient releases. and for my taste, some of the best short tracks Prurient has ever done. really just perfectly executed all the way around. can't help but listen and think that this one had to have a huge influence on all of the "romantic" and mellow PE that's come out over the past 5 years.
But Prurient has many other great releases too! With a discography as big as his, not everything is a winner, and some just suck, but on the whole most things are pretty fucking good.