The L-Train doesn't just do covers songs. He does cover symphonies. He does a few vocal tracks, which are pretty great, but his true crowning achievements are his "Symphonic Metal Tributes", in which he does an orchestrated metal cover of all of the most remembered songs from a show, film, or game.
He's done a Symphonic Metal Tribute for Pokémon, The Legend of Zelda, and even Steven Universe (which isn't a game we know but we had to mention it because it's just too good not to). The authenticity with which The L-Train recreates such famous songs with completely different instruments demonstrates a level of true familiarity with the music, and a love for the medium as a whole.
Put on some L-Train, lie back, close your eyes, and pretend you're out at the theater hearing a live concert. It'll work wonders. Check out his bandcamp here.