Also, for more formulaic but energetic, engaging music:
Antti Martikainen, Yasuharu Takanashi, Adrian Ziegler. There's also Miracle of Sound, that makes great trailer-like videos complete with his own music kinda promoting video game franchises and iconic videogame characters/settings
Plumb: This is about as epic as my collection gets:
https://www.youtube.com/watch?v=nbhUApfWMXA Not counting all those Pink Floyd albums. (The Wall might be the most epic thing ever)
The Who, also. I'd like a full, flamboyant animation series of some of their albums. That would work!
If you like classical, there's Musorgskiy,
and of course, we're on GoG, so you can listen to Thronebreaker OST that was free for a while some months ago. Always underrated
PS: I forgot the "grandfather" of modern epic music: John Williams!