Robust plugin and good support

This plugin was the only one I could find, even out of many paid options, that had the flexibility to do what I needed. I needed form users to be able to select which mailing list they wanted to subscribe to, and then the submitted form would route the new subscription to the appropriate list. Every other plugin required that the list be baked into the form, rather than being conditional on user input. The plugin authors were very helpful too in guiding me in the correct setup for my requirements. Thanks!!