24 Hour Wal-Marts -- or "Super" Wal-Marts as they were once called -- really aren't that amazing. But they tend to be low-key for this sort of thing. It's been a while since I've been the type of person that ventured out of the house at midnight, but years ago, before I moved a little further out into suburbia, I used to live about five minutes from a shopping complex that had both a Wal-Mart and a GameStop. I remember buying Brawl and Mario Kart Wii from that Wal-Mart at or shortly after midnight with no fuss at all (i.e. no lines, no arguing with the employee about whether or not it was supposed to be available or anything).
I also remember GTA IV's release. I didn't really care that much about getting it day one, but I was still up the night it released so I decided to swing by and see what was going on. There was a long line outside the GameStop. I walked into Wal-Mart at about 11:45, and it looked like there was maybe ten people waiting for it. And since it was a 24 store, they were obviously waiting inside the store by the electronics department.
Like I said, I understand if you want to hang out and make a night of it with a bunch of fellow gamers around. And I know some places set up tournaments or what-have-you to make it more of a big deal. But if all I'm interested in is buying the game? Yeah, I'd just go to the Wal-Mart.
Thankfully, I can just buy digitally these days and not worry about any of it.