I'll throw in with the Houston crowd here. Our shows are, on the whole, pretty good. You can catch one, sometimes two shows almost every weekend out here. The saturation effect is bad for everyone. It is tough to convince promoters not to put on a show as the majority of their money is made selling tables ($80/table here), even though admission is declining. The most recent panic has made dealers reluctant to give up tables, and there is still a high demand to get tables despite low turnout.
This all being said, for a buyer, it is a good time to go to a show in the Houston area. You can see and hold a ton of different guns in a relatively low pressure environment. Prices for new guns tends to be competitive if not better than local gun stores, and even competes against on-line vendors when you account for the transfer fee. Even ammo is starting to get better down here. Plus, you can pick up odds and ends that are difficult to find elsewhere. I'm probably going to end up at the Pasadena show to buy some cleaning supplies from a certain vendor I know will be there. He has exactly what I want, and I can't seem to find it elsewhere. On top of all of this, you do still get to see older, collectable guns (old colts, etc.), and I'm seeing good values on police trade-ins.
The breakdown of stuff at gun shows can fall into these categories:
Junk (sheets, art, jewelry, etc.)
Food (some jerky ain't bad though)
Knives & tasers (some junk, some decent)
Gun-related junk (cheap/crappy holsters, lights, lasers, scopes)
Quality accessories (holsters, lights, lasers, scopes, & sights)
Ammo
Old, worn, used firearms (some may be collectable, others are junk)
New commercial firearms
Used recent production firearms
Collecter grade firearms
Good promoters will manage their tables to try and keep shows more on the side guns (bottom of the list) than junk (top of the list).
I've started splitting a table with a friend of mine at some of the shows here in town. For $40+parking, I can spend two days at the show at a fixed location, and have the opportunity to sell some guns, mags, ammo, and/or accessories that I no longer have a need for. Plus, I bring cash and have the opportunity to see many of the guns people bring through the door. Two shows ago, I bought a couple of nice .22 rifles, while selling some other not-as-nice .22's. Fun times.