I'm a fan (and you should be too) because... Three days Grace is the best band ever!
They play beautiful music that actually make sense! In the music videos they express theirself beautifully and it makes it easy to understand the topic of the song if you not are that good in English.
And if you have had a bad day, you can play their music - extremely loud if you want to - and it really helps. I love them almost more than anything else! And you should too!