Most popular shows have a 2-8 ticket maximum.
On the day of show usually between 2-4 PM they will release any unneeded tickets from the artists allotment. I bought really, really good Dead seats about 15 years ago this way. You can always try that. Often the box office knows if there will be a release earlier in the day if you ask. These will only be available day of show at the box office, not through Ticketmaster, and the box office won't always tell you over teh phone.
Because I'm a music critic for a magazine here in Orlando I usually get free tickets to any show I want to go to (I sometimes buy them for shows I'm not reviewing). Usually they give me two tickets, but usually when I'm "working" I prefer to go alone.) So after I get my tickets from will call, I look around for a neatly dressed "normal" person who has that "I need a ticket" look and give them the extra ticket. They are usually shocked and want to know how much I want for it--I ask them to make a donation to the local food bank in the next few days instead. Puts a smile on their face and helps out a good cause
Anne