I love Mannheim Steamroller music. Can you recommend other similar sounding instrumental music?

I thoroughly love "Do you hear what I hear?" It's as calming as you get. And "Good King Winsellas" is energizing.

Can you recommend any classical, orchestral, or instrumental pieces with elements of heavy brass, drums, or violin, piano, or piccolo that I should listen to? Or even something new that I should try?

Trans Siberiean Orchestra is great - but check out the music of Chip Davis (the early stuff) he was the main guy and instrumental force behind Manheim.

Check out Trans-Siberian Orchestra.