San Diego Comic-Con (or just "Comic-Con" as the world is becoming to know it). I first went in 1992 and have both embraced and lamented the changes made as Hollywood took control.
(For the record, I've blogged about Comic-Con before: here, here and here. Plus, I'm still trying to find the owner of the camera I found last year.)
Hollywood has (much to the traditionalists' dismay) invigorated Comic-Con, but also made it much too crowded. Last year, I waited in the Hall H line for literally (and I am using "literally" in the correct, literal sense here) four hours at one point. My wait was in part due to camping-out fans going into the hall early for panels hours later than the panel currently happening(such as those depicted below, waiting for a "Lost" panel in 2009). This has been getting worse each year, for several years.
Comic-Con has got to cut down the waiting in line. It's unhealthy for the sun-averse (such as myself) and prevents me from enjoying as much of the show as I'd want.
So two things. One: Clear out the rooms between panels. (Hypothetical) Why is my Doctor Who panel full of Twilight fans waiting for good seats for their panel six hours from now (or vice-versa)? We could fit 4,000 more Doctor Who fans in here.
Second: How about online reservations for panels? Why should I have to wait in a six-hour line for Hall H and have no guarantee of even getting in? I could be going to the Roy Thomas panel in the meantime. Put aside a certain number of seats in each Hall/Ballroom/Conference room (say half) and let people make reservations for them online. Let registered badgeholders reserve one panel per badge per day. Let them print out a bar-coded ticket for the panel which means I just have to get into the short pass-holder line. Once that line clears, let in others until the room fills. Technology can do that these days.
Crowds (such as those in the picture above) will continue to overwhelm Comic-Con, there's not much that can be done about that without severely restricting ticket sales. But certain measures (such as having reservations for panels) can make the experience of wading through the crowds more enjoyable.