SAN DIEGO -- San Diego Comic-Con closed its doors Sunday and the City of San Diego is thankful for the visitors, 10News reported.

The convention is thought to have raked in millions of dollars and city officials believe that when the final tally comes in, this may have been the largest Comic-Con to date.

Fans were drawn from all over the world for the all-star panels and premiers. The elaborate costumes are also a show stopper, 10News reported.

"San Diego is like Christmas to us," one attendee said.

Each attendee's interests determine the highlights of Comic-Con. For many, it is simply the thrill of being ahead of the mainstream.

"You get previews of movies that are concepts only, and then later on they become box office hits and you go 'Oh sweet! I've seen that before all of you!'" Erin Perea said.

For other convention goers, it was meeting their idols.

"I got to meet Joss Wheedon yesterday and I'm a huge Buffy the Vampire Slayer fan. I'm a black belt in taekwondo because of that show," Michelle Prenez said.

The final numbers have yet to be received, but officials said they expect attendance over the four-day event to be over 125,000 people.

The convention has steadily grown in popularity so much so that many worry it may have out-ground the San Diego Convention Center, 10News reported.

"When we moved here, when it first opened, we didn't know if we'd actually be able to utilize the entire facility. We did, even with the expansion and now of course we're busting at the seams," Comic Con Spokesman David Glanzer said.

San Diego's contract with Comic-Con expires in 2012, leaving some fans fearing a departure.

"That's terrible. It sucks. I don't know where it's going to go, like is it going go to Vegas or something?" Riverside resident Mike Hillenburg said.

"Our contract is up in 2012 and that's really not unusual. Typically we start negotiation about two years out so we'll see what happens beginning next year," Glanzer said.

Tickets to Comic-Con sold out two months in advance this year. While its future in San Diego may be uncertain, fans said wherever the convention is, it is where they will be.

"It's a once in a lifetime experience but if you get offered the chance where you can come again, there's nothing like it so you just have to keep doing it," first-time visitor Tyler Ballard said.

The US Grant Hotel hosted the first Comic-Con back in 1970. Since then, it has grown into an international event that has attracted more visitors each year.