I've had countless tickets from ticketmaster with no issues. It's always been a great experience.
I must warn you though do not purchase VIP tickets through them! I have been bounced from pillar to post on my first ever VIP purchase, which was a special present for my girlfriend. They are willing to sell you the ticket, take your money, and then when you have a question for them on the details, they don't want to know!
Terrible experince, will not be doing that again!
given wrong tickets