Having the bartop touchscreen set up for a little while, I really like the Real Deal slots and video poker for a little grown up action. (The only problem is that you at some point need to input the amount with a keyboard because there is no virtual keypad. I have a wireless keyboard with the receiver being inside the cab.) I also have Winbox set up as my jukebox program. It works great with a touchscreen.
I currently have Mala running as the frontend, but I'm going to probably give Gameex a try. I have been goofing around with it on my regular computer. It seems to be more touchscreen friendly. Mala runs great, I use my joysticks, and buttons to navigate it.
I'll come up with a list of all the games that I like to play that work well with a touchscreen. I've tried a lot of hit and misses.