Requiem is incredible, one of my all-time favourite missions of the series. The atmosphere was absolutely bang-on, from the opening segment at the crash site to the bit where you emerge from out of the caves to see that massive shifting spires, I still get goosebumps. The music here was actually implemented [i]perfectly[/i] which contrasts with the rest of the game where it's just way too quiet. The Forerunner cathedral which is being gradually reclaimed by nature was amazing too, Legacy adds so much to the ambience of that bit.