Paid plugins (with support) are the way to go for getting the highest quality and I've had great experiences with them. Some of the ones I've had great luck wit

Paid plugins (with support) are the way to go for getting the highest quality and I've had great experiences with them. Some of the ones I've had great luck with on my site are Advanced Custom Fields, Gravity Forms, and most recently FacetWP. Edit: that said, there are also high quality free ones as well