www.youtube.com/watch?v=h9tJ57…
www.youtube.com/watch?v=rnQBF2…


One Piece has music for every mood happy, sad, or epic since it's all orchestrated. 

www.youtube.com/watch?v=zuYQB5…
www.youtube.com/watch?v=F7d33V…
www.youtube.com/watch?v=SYZao9…


But they also have great pop and rock openings from an old to new anime feel. 
www.youtube.com/watch?v=5GUPto…

 My favorite is Fight Together: www.youtube.com/watch?v=UGreqB…

Free!Iwatobi/Eternal summer has some pretty chill stuff with some great openings
www.youtube.com/watch?v=-b205Q…

www.youtube.com/watch?v=9pdePD…

www.youtube.com/watch?v=rOlIzM…

Attack on titan has a lot of epic music especially the opening and endings but also a lot of really sad emotional fan music.

www.youtube.com/watch?v=Y2gROO…
www.youtube.com/watch?v=DwLV52…
www.youtube.com/watch?v=w-xXsp…

www.youtube.com/watch?v=6V5BK3…
www.youtube.com/watch?v=HgPawJ… Lizz is a great fan cover/remixer.

Her KingdomHearts music will kick you in the feels 
www.youtube.com/watch?t=11&…

I recommend vocaloid music and if the robitic voices aren't your thing I suggest the Nico Nico Douga/chorus fan covers. Because they make some really good stuff. 

Regular vocaloid:
www.youtube.com/watch?v=8kX5_6…
 www.youtube.com/watch?v=06d8Sw…
www.youtube.com/watch?v=b-IYDi…

 Some of my favs by Nico Nico artists:
Zebra + Rabit Just Be Friends:
 www.youtube.com/watch?v=XK1gqX…

Matrysoshka Lon+Soraru version
 www.youtube.com/watch?v=46sEGf…

Rolling Girl Chorus: www.youtube.com/watch?v=9gJ1pr…

Panty and Stocking has some good stuff too on their soundtrack

www.youtube.com/watch?v=F0fR6C…
www.youtube.com/watch?v=zsJzJR…
www.youtube.com/watch?v=ChjJEU…