I use phpArcadeScript for my arcade, and I can honestly say that it's probably the best. It's certainly better than gameScript, plus... it's only $30. www.phparcadescript.com I'm not meaning for this to be an advertisement, but more or less a thread with my opinion. I started using it about three months ago. My arcade is http://www.gamerunlimited.com/arcade.php It's been a great addition to my site, and AdWords loves it. The clicks you get for an arcade using Adwords is pretty astonishing.
There are sub categories,rss feeds,submit games option,staff option just to name a few in the latest version.And it looks different too.Looks much better I'd say.