If you like some music you heard in an anime, look up the artist and do some snowballing. That way you can easily find more music that you like.

If you want to find animes where the music is good, and not only find music to listen to, maybe (just some examples, definitely not complete):

• Hunter x Hunter (2011): Awesome endings (ed 2 for example), as well as ost. (Old pre-2011 hxh adaptation also has good music afaik.)
• Call of the Night: The op (or ed?) inspired the manga, and then in the adaptation they took the song. And the other op/ed music was then also made by creepy nuts.
• Yamato: Op goes hard, and fits great to the space fights.
• Terror in Tokyo: More sad than epic, ed/op and ost fit well.

I absolutely love Dungeon Meshi both openings get me in a cheerful mood. Ranking of Kings also has a beautiful story and the intro gets better the more you know about the story. Both are not particularly ‘epic’ though.

The intros of Chainsawman, Heavenly Delusion and Dandadan (both of them) are also some of my favorites. Mob Psycho 100 intros (I think all of them) are absolute bangers.

Here is my anime intro playlist

Dan Da Dan

Aggretsuko

Nobody’s mentioned the opening to Tengen Toppa Gurren Lagann? Nobody? Come on.

Runner up mention to Kuusou Rumba from the second season opening of Sayonara Zetsubou Sensei, especially for any players of Katawa Crash! back in the day who will probably never get it out of their heads.

Tokyo Majin Gakuen Kenpucho-to (sp?), all op/ed performed by ACID I believe.

Sayonara Zetsubou Sensei had banger after banger for its openings.

One Piece OP1 is a classic

Gintama’s early openings and endings are also really good. Pray and Mr. Raindrop are great.

Would be remiss if I didn’t honorable mention Eden of the East just straight up using Falling Down by the band Oasis (the guys who wrote Wonderwall).

I love the one piece trails (not quite sure about each season)
Also Mashle and Gachiakuta

The second Ending of Jujustu Kaisen is probably my all time favorite anime Ending. The animation is fantastic, and the song is gorgeous.

I can’t really tell if you’re looking for recommendations of good anime with good OPs, but this is my playlist of good OPs and EDs. https://youtube.com/playlist?list=PLTRuZiBzA6WtS5z2G0hadW7O9ceWD0N-0

The first Death Note opening is kinda terrible but the second one wasn’t too bad iirc. I like the first Dandadan theme, especially together with the video.

Tokyo Ghoul’s OP is a banger. So is the first AoT OP.

Slayers Next. Irresponsible Captain Tylor.

Yes, I know I’m old.

Log Horizon had an unbelievable opening and ending duo.

Hikaru No Go half of the reason why an anime about go is so epic is the amazing music.

Gachiakuta or Dan da Dan.

Both have incredible openings and story.