I'm about to be 21 & sadly, I have never experienced the shady arcades you guys speak of so fondly. Hell, I doubt I've ever been to any kind of real arcade.
A few of the roller skating rinks I used to frequent when I was younger had somewhat decent arcades, but it's been a number of years since I've been to any of those places. The closest thing to a "real" arcade I've ever been to was a place in some mall in Louisiana that I can't remember the name of. It was obviously a more kid-friendly place, but they had quite a few cabinets. It was predominantly redemption games, though.
I also used to pop into the FYE arcade at the mall here but, again, mostly redemption games. They did have Tekken and Soul Calibur, though, which were mainly what I played in there. That entire FYE closed down recently though. There is a Dave & Busters there as well, but it's full of drunk idiots most of the time so I try to steer clear. They did have Donkey Kong & Galaga, though...that's about it for their actual cabinets, though. Everything else is either a light gun game, newer sit-down racing game, or redemption, redemption, redemption.