Hold Your Colour has some of my favorite Pendulum-songs though, songs like: Another Planet, Still Grey (depending on what version you have), the title-track obviously, Girl in the Fire, Blood Sugar (again, depending on version), and Plasticworld.
In Silico has 9000 Miles, Granite, Showdown, Propane Nightmares, The Tempest, Visions and Midnight Runner.
Immersion has Encoder, The Island (both Parts), The Fountain and Under the Waves.
Well, I really love all of their albums, these are just some of my favorites.
I might also add that Voodoo People would be high on my list, but I don't think there's a studio version of it.