That is really too hard to just choose one band, song or artist! There are so many I love for so any different reasons. Right if I had to narrow it down to maybe top 4 of each? It would be:

My favorite bands: Oomph! Miss May I, Bullet for my Valentine, and 2NE1.
My favorite songs: Hard one... can’t possible choose.
My favorite artists: As above

Two of my top favourite bands Oomph! and 2NE1 do songs in another language (German and Korean) which I find a lot better than their English versions.