Brunuhville is another one of the “big names” of new age fantasy music / celtic music realm on Youtube. His channel https://www.youtube.com/user/BrunuhVille is closing in on Adrian von Ziegler’s level of popularity and it’s all very well deserved. His style is professional and very inspiring. While Adrian focuses on more ambient side of things, Brunuhville excels at cinematic and modern orchestral style, sounding very soundtrack / epic at times. I especially like his works that focus on that high adventure and romantic style, combining big orchestral layers with beautiful melodies.
If Brunuhville is already well known to you and you are his fan, I can definitely recommend listening also to Celestial Aeon Project which is very inspiring and beautiful celtic music / fantasy music project of finnish composer Matti Paalanen. While his popularity on youtube is still very modest, I think the quality of his music and his sound is on par with the big names. Take a listen to this epic fantasy release from him for example: