I'm immensely late to the party, but I just finished Halo 5.
First of all, let me just say that I really don't understand all the flacks this game received for its campaign. It's different, fine, but it's fresh and it's certainly exciting. It's great, even.
Team Osiris turned out to be fantastic and the ending only made me more excited for the next Halo... much more than Halo 4 did.
But I digress -- the real star of the game is its soundtrack, composed by the talented Kazuma Jinnouchi. He used to work for Konami, mostly on Metal Gear Solid 4 and Peace Walker, then moved to 343 to work on Halo 4 and 5.
However, something happened between Halo 4 and 5 -- the soundtrack feels much more solid than it ever did for Halo, even when Marty was on board. It's not the same ; it's more orchestral and high-stakes than Marty's. It's different.
But BOY is it good! Maybe it was the focus on Team Osiris, giving us new themes, or the re-work of 117's theme into Blue Team, but everything feels cohesive, grandiose and dear god did it pump me up during gameplay.
I won't use hyperbole like 'THE BEST' or 'OF ALL TIME', but it's amongst the most pleasant video game soundtrack I've heard, standing proud and tall next to Journey, Metroid Prime, Red Dead Redemption and Chrono Trigger for me.
Here are a few tracks ; it was very hard for me to select what track would represent the game best, though...
The Trials -- Blue Team is tested by the Warden. Classic Halo theme remixed with 117's and Blue Team's.
The Light is Green -- Introducing Team Osiris. Their mission : retrieve Dr. Halsey and kill Jul'Mdama. Features Team Osiris/Locke's theme, mostly.
Dominion -- The emotional turning point in the story.
John realizes how far Cortana is willing to go to do what she thinks is best.
Anyway there are tons of songs I could share, but the OST comes with 2 discs. It's really worth a listen : it's available on Google Play Music All Access and Spotify. If you're in the mood for a good sountrack, video game or not, give this a go!