The best RV over the air antenna available is still the Winegard Sensar amplified head VHF/UHF crank up antenna. Add the Wingman add-on or the newer Sensar IV head and it's even better for UHF reception. To really pep up reception even more, add the SensarPro inline amplifier and signal finder. If you're into technical details, here's a link to some comparison testing done by a forum member and professional broadcast engineer:
Batwing vs.BatMan vs. Jack: The Results..