They are all great effects, but you should really choose the effect you like the most. The methods for all three are easy to do and workable of course, but just go with the effect you like the most.
Personally, I thing Panic is the best effect Theory11 has released because... well, it's amazing for the spectators. Distortion is very cool, and it will absolutely get good reactions, but like Eddie said, it does have a few disadvantages. Prophet is money magic, which will get people interested no matter what. So all 3 effects are amazing without doubt, but I like Panic the best.
Panic's angles are good, the reactions are very vocal most of the time because of the visual simplicity, and it isn't difficult to perform at all. It takes lots of practice to make it look good, as this is a heavily presentational effect, but the gimmick and the method are pretty straight forward to use at first.