- Halo 1 - Halo 2 - Halo 3 - Halo 4 and 5
Halo 4 and 5, definitely
As nostalgic as Halo 3’s armor is, Halo 4 really made Chief look like he has the power and weight of a Spartan. The armor feels heavy and Chief actually feels like he can punch a tank into pieces, whereas 3’s armor felt more of a protective layer of armor, rather than a full exoskeleton suit.
Halo 1 to 2 and 3, naturally.
Halo 4 needed a way to introduce the new armor. The explanation of the change between 1 and 2 made sense, and was a fine way to adapt the stylistic change. 4 was abrupt and made no attempt, it just changed while he was in cryo. For that I am biased against it.
Halo 2 and 3. The Mk. VI was the greatest!