The best evidence that UFOs exist are the countless sightings by experienced pilots, civilian and military, who have seen objects move across the sky at incredible velocities and turn at such sharp angles with such G-forces that a human being would have been torn to pieces, providing he/she could move at such velocities in the first place. Or else, pilots seeing brilliant, spherical objects repeatedly coming apart and going together. There have also been many radar sightings of fast moving objects that have disappeared right off the radar screen, sometimes demonstrating similar gravity-bending maneuvers in the air.
Skeptics have argued that pilots are just as fallible as terrestrial witnesses in misidentifying venus, meteors and other mundane aerial phenomena as UFOs. A weak argument due to the fact that these pilots are highly-trained, disciplined and log many thousands of hours in the air, such as jetliner and military pilots, who certainly know the difference between a UFO and Venus. It's an absurdity and an insult to many highly-experienced pilots, some even with military experience. The skeptical argument seems to be based on part in insulting and ridiculing people.
If the pilots did not know the difference, they would be crashing all the time, thinking Venus or other mundane aerial phenomena were UFOs. Additionally, the chatter between pilots, and ground control would be of the countless UFOs. Obviously, a trained and experienced pilot knows the difference. Some airliner pilots have even seen UFOs bigger than aircraft carriers, not a bright, stationery pinprick in the sky like venus or a streak across the sky like a meteor.
A recent Larry King show, highlighting the anniversary of the Roswell UFO crash, also featured Bill Nye, the Science Guy, representing the skeptical viewpoint. He openly ridiculed the argument of Dr. Edgar Mitchell, Apollo 14 astronaut, much to the consternation of Larry King. He showed a ridiculous series of obviously-hoaxed photos of a crashed UFO recovery, citing the general public as being on his side in his debunking. The trained skeptics and debunkers are part of the proof that UFOs exist-they deny credible evidence, phenomena...and the word of credible people such as pilots and astronauts.
A previous 'Larry King' segment on UFO's (in part, brought on by the recent UFO flap in Stephenville, Texas) demonstrated the weak and fallible argument of the skeptics to sightings of UFOs - even openly debunking a US military officer who touched a UFO in the famous case of the Rendlesham, UK UFO landing as yet another misidentification and misinterpretation (remember the CIA-convened Robertson Panel, in 1952, who started the policy of UFO debunking).
Pilots, with their very discriminating eyes, have seen UFOs almost since the beginning of manned flight. Evidence suggests that military pilots have chased UFOs all the way up to today, some allegedly even been brought down by UFOs. During World War II, US fighters and bombers saw small flying objects following them, executing incredible aerial maneuvers; these objects being referred to as 'foo fighters'.
Ancient accounts are laden with accounts of flying objects and beings who descended from the stars. Many ancient texts speak of flying machines and aerial battles sometimes fought by them. The ancient narrators openly spoke of their design. They, too, were also not influenced by Venus, meteors and other prosaic phenomena. In fact, they had an intimate knowledge and understanding of the stars and planets, and were not influenced by the mundane aerial phenomena...much like the pilots of today.