TrapTune - Audio Demo
TrapTune is (not just) an automatic tuner which can give you everything from subtle pitch correction to the strong artificial Cher-effect. Combine it with a second voice harmony, doubler and special FX section to get a vocal track that really stands out.
Listen to the what options the plugin gives you.
Get a trial version at: https://unitedplugins.com/TrapTune/