SNECMA Coleoptere early VTOL testbed with annular wing.
Get up to about 300 metres before transitioning (slowly) into level flight.
I have yet to find a dignified way of landing, the most effective way is to fishtail at ground level to drop your speed to about 100, then pull up vertical and lower the throttle. Make sure your descent speed is less than 20 m/s or it will flip nose down. AG1 toggles rocket motor to smooth out the lag.
Gif in action.
KSP version 1.2