It's been said a million times before, and please feel free to argue, but: Crowd interaction.
I want to see LP make their shows fun again. They're on the right track now with wanting to make the sets more high energy, but just standing there and playing song after song without saying anything besides the generic "Thank you" and "How are you guys?" doesn't exactly keep the energy up. I've been to a decent amount of shows, and I've seen a lot of bands that sound great (I think LP sounds fantastic live, even on Chester's off days), but don't say a word to the crowd, and, surprisingly, it gets boring. I'm not asking for the guys to start monologuing or anything like that. Go listen to a 2007 or early 2008 DSP. That is enough crowd interaction to keep the show pumped and interesting. Tell the crowd when to jump, when to put their hands in the air, when to clap, have them make some noise at certain points, anything. Just listening to them play song after song does get boring; it becomes less of a show. They just need to get the crowd involved in the songs again.