I have the first 4 installed. Just on the basis of the volume of work and updates involved (a new one almost every day), I'm going to go with eBux. Otherwise, I'd have difficulty deciding, as the others are very useful.
I tried ucash 3 times and couldn't get it installed, eBux went up the first time with no problems. Updated almost daily with the author actually going over the problems and requests and giving very quick responses. Should not be hack of the month, but hack of the year!!!