Doctor Who: Unbound

An audio play spin-off of the Doctor Who franchise where different alternative scenarios from throughout its lore are explored
It first ran during 2003 through 2008, and has just been revamped with the "Doctor of War" alternative storyline this year

Original series:
https://www.bigfinish.com/releases/v/doctor-who-unbound-1-8-collected-2757
Doctor of War 1 and 2:
https://www.bigfinish.com/releases/v/doctor-who-unbound-doctor-of-war-1-genesis-2596
https://www.bigfinish.com/releases/v/doctor-who-unbound-doctor-of-war-2-destiny-2597