This form plugin is GREAT! I have used other paid and free form plugins and have primarily used CF7 for most of my form needs but I'm thinking that Ninja Forms might be taking over that a little. I just starting using this form plugin but from initial results it is a GREAT plugin. It works very well and doesn't have many problems, like some of the other form plugins do.
I also am loving the affordable pricing structure. The main part of the plugin is free but the added features are an affordable price for anyone. This is great because if you want it then you simply pay for it - no more paying for things you will never use. Also, their customer service was faster than I thought it would be and they were very nice and I can't wait to see what other features and things they come up with.
Ninja Forms was just added to my top ten plugins for every site.