@Alfch most metal songs. There's a bunch of them but if I had to pick, songs by 
dragonforce Through the Fire and Flames might be good since they're pretty lengthy and geared towards fantasy if you need to pull away from reality. 
Disturbed if you need it to be more like heavy rock. Usually the easiest introduction. 
Apocalyptica if you like cellos. 
Rammstein's also a popular choice. I really can't say much about lesser known ones because there's a whole lot of them and I'm in the opinion that this genre, unlike others, are in that weird mix of popular but not really so I dunno.
If you want metal versions of famous songs, then try looking into 
Frog Leap Studios' YT channel or Alien Ant Farm. 
If you're looking for something just generally bops, then have a go at 
Steam Powered Giraffe's music, like Latum Alterum or Hot on the Trail. Mystery Skull's also great like their song 
Ghost.
For something pretty upbeat, try 
Goldfish's songs like 
Three Second Memory or 
Kill It 4 the kids by Kill the Noise.
If you're into something funky, try 
Ghost's Square Hammer or 
They Might be Giants Ana Ng, 
Don't Let's Start, or 
You're on Fire.
If you like some 80's vibe, try 
I Don't Know How But They Found Me's songs, like 
Choke or 
Sugar Pills.
For something a bit more chill, there's 
Gorillaz'; try 
Let Me Out.
If you want rock, then 
Siames is also pretty great. Try 
The Wolf for starters.
If you need instrumentals, I gotchu, too. Try 
Wings of piano from 
Deemo if you're looking for something that's not classical.
Parodies are pretty great too. Check out 
The Merkins. Their parody of Faith, 
Fate, was pretty great and their singer in 
Man In A Box really captured Alice in Chains. 
Weird Al Yankovic's also pretty famous. I particularly like 
Word Crimes and 
White & Nerdy. The Youtube channel, 
thelonelyisland, really bops, too.
Cartoon songs are surprisingly catchy, too. Try Disney's 
Powerline songs or 
Quest for Camelot's If I Didn't Have You. Well, famous one's aside, Spies in Disguise kinda went under the radar but their songs really hit the spot. 
Rocket Fuel, 
Freak of Nature and 
Then There were two to kick things off.
How bout rap? If you lean on the heavy side of things, I can recommend 
NF. 
Vin Jay for melodic raps or 
One-T & Cool T's The Magic Key.
You like jazz? Try 
Robyn Adele Anderson's covers. 
There's also country. Not everyone's cup of tea, but the blues are great. Just try 
Blues Saraceno's Grave Digger or 
Nick Nolan's Life of Sin. Raury makes great songs, too, like 
Devil's Whisper.
How bout we go to something that just screams, "THIS IS THE INTERNET!"?  Try the 
Chicken Song by 
J. Geco.
Anime covers? Try 
Maki Oyama's version of 
Cha-la Head-cha-la.
I don't have a particular song preference, but I do tend to like blocking out the world, so if you're interested, dm me and I'll send you my youtube playlist. I skipped out on R&B and other pop songs cause, well, they're popular so I think you already know most of them. I suggested the ones most people I come across haven't heard of.