The Denver Flagship does it the best.... at 7 in the morning (maybe 8, look up the time if you want to go) they pass out different colored raffle tickets. Right before they open, they draw tickets and assign each color an entrance time. When you get in, you have a limited amount of time to shop. When time is up, they kick you out and do a restock before the next crew rolls in. Around 12 or so, it opens up and you can come and go as you please.
This makes it so much better than waiting in line or camping out. No matter what time you get assigned to, you have a good shot of getting good gear