On which concerts/festivals have you been to?

I really enjoy going on concerts and festivals so I'm interested on which concerts or festivals some of you have been to.
For myself:

• Bullet for my Valentine
  
• Slipknot
  
• Hollywood Undead
  
• System of a down
  
• KoRn
  
• Skrillex
  
• UKF
  

I may have forgotten one or two, not sure.
Going to Bring me the Horizon and The Prodigy next.