Okay that poll took longer than I expected, and I didn't know the thread already opened.
I selected twin-single hilts because the lightsabers don't have any mass. You might as well just turn a shoto into a standard saber to balance it properly. One option that I would have added, but hasn't been used in SW was twin shotos because they are much like escrimas.
Single hilt-shien form is another I favor because it can take a traditional saber and really turn it into something different than Darth Vader and Luke Skywalker. The single hilt is just boring, but Shien reminds me of a katana when held back-handed.
Tonfa-style was interesting, but I don't find them very flexible for anything other than twin-saber fighting. Also are difficult to work with.
Saberstaff: let's just say that they are MUCH less effective when you only have a short hilt to work with. If it was just a standard staff, then you'd have something deadly.