I stole like all of these from youtube :3

Battlefield 1 OST - They Shall Not Pass End of Round theme extended 2

Joel Nielsen - BMS - Black Mesa Theme

Savimbis Pride

The original Plague Inc and Plague Inc: Evolved soundtrack, featuring all of the tracks from both games - including the haunting main theme, the paranoid notes of Neurax worm mind control, the aggressive style of the zombie-producing Necroa virus and Simian Flu theme.

Enjoy it! ;)

Plague Blossom (Main Game Theme Song)

Superposition - Quantum Echoes

Remix from the fantastic OST from Half Life 2

Triangle at dawn-path of the Borealis (Remix)-1476246970033

Triage At Dawn - Path Of The Borealis (Remix)

No one made it on Soundcloud, but i liked it, so here it is.
Composer: Álvaro Ródenas Fernández (Abetus)
YouTube link: https://www.youtube.com/watch?v=Q4P3vzLTGJU
Note: None of this belongs to me, all credit goes to the owners.
P.S. Sorry for the pic clipping.

Plague Inc Evolved - Desperation For A Cure Theme

Half - Life Opposing Force OST - 16 - Chamber

I did not make this it was made by Joel Nielsen on the black mesa team. All credit goes to them. 
-Black Mesa SoundTrack 12 Ascension

Black Mesa Xen Soundtrack 12 Ascension Joel Nielsen

I did not make this it was made by Joel Nielsen on the black mesa team. All credit goes to them.
-Black Mesa SoundTrack 21 Ascension Reprise

Black Mesa Xen Soundtrack 21 Ascension Reprise Joel Nielsen

[Plague Inc. OST] This is the song that plays while playing the new Cure gamemode
(DISCLAIMER: I do not own the song, this is owned by the creators of Plague Inc., NOR am I, the uploader associated with the devs.)

Plague Inc Evolved - Desperation For A Cure Theme

Benjamin Wood