I thought 343 nailed the feeling of controlling a Spartan, with the power and weight that implies. The heavy thudding footsteps, the slight shifts in the HUD to imply we've got a helmet on, the video feeds relayed onto it. And then especially in cinematics, the Chief is a hugely intimidating figure, dwarfing everyone around him. He is portrayed as a big walking tank in a way that just didn't come across before. And 343 pulled this off while restoring fluid movement and agility to the series, after Reach. It was something Bungie struggled to portray without impacting gameplay (again, Reach) but 343 hit it out of the park.