Chapman Stick
My first Touchguitar was the Chapman Stick. I tune it in Ascending 4ths on the Rhythm side with 2 bass strings (left hand uncrossed) and Ascending 4ths on the Lead Side (right hand uncrossed).
ADG
The ADG was where I found the uncrossed tuning and began playing seriously. I currently tune it 4ths/4ths Baritone tuning in the Rhythm and Guitar tuning on the Lead side. It has passive pickups and a very warm sound.
Warr Guitar
The Warr Guitar is the Artisan model with piezo pickups, midi and has a Double 4ths tuning. The Rhythm side has 3 bass strings
Box Guitar
I own a 12 string Box Guitar that is 25" Guitar scale. I primarily bought it as a traveling guitar but I like the sound and the range. I'm able to go much higher than I can with the other instruments. Originally I started my touchguitar quest because of Stanley Jordan. I was not able to make it work on a single guitar, though I tried for years. The Box Guitar is the perfect solution for those who want the Stanley Jordan sound. I'm enjoying it immensely...
NS Stick
The NS Stick is a 8 string Bass tuned in 4ths and the strings are split 4x4 with two different pickup routings.
Megatar
I don't own a Megatar but I once tried one and it was very playable. It's also affordable and a good option for beginners.