the good sites are the ones you make money on and that can vary from model to model. you can't know until you try. some can recommend sites and when you try they don't work for you..so just check out the reviews on each site and all the info, before signing up.
I worked on xHamster too a few years back. it was good until it wasn't. Bongacams is similar to the other 3 you mentioned, but i likes it the least and couldn't work there because of stupid rules such as "no watermark".
You can try some private based sites too..see if they work for you. i recommend iFriends and adultwork.
Good luck!
