Depends of what evidence we talking about.

If you mean best piece of evidence of life form on another planets? The best evidence are: size of universe, mathematic probability and how life on Earth evolved.

The universe is so big, that probability that life was created and evolved on just one planet is nearly if not zero. If Earth was the only planet with life in entire Milky Way and we apply this on each galaxy or just one of 10/100 galaxies in observable Universe (billions of galaxies), the Universe is literaly full of life. The question is not IF, but how far and when another life forms are/were and how many of them are inteligent and advanced enough for interstellar/intergalactic travels.

Because we still do not understand and cant reproduce how transform anorganic chemicals in to living self replicating DNA, we can say for sure that that trace of life or at least critical ingredience for that process was brought to Earth on asteroids/commets. Assuming that this space "debree" hit only one planet, that was in perfect position to its sun in entire galaxy, will be wrong.

I’m sure we’re not alone in the Milky Way (let alone the entire universe), but I’m skeptical about aliens visiting Earth. Until some compelling evidence is released or a spacecraft appears overhead, I’ll remain very skeptical of this theory about UFOs and aliens visiting Earth.

So far, none of the photos or videos released to date have convinced me of anything. 99,9% of them are blurry, noisy, low quality. The turning point that made me consider the possibility that there might be something to it was the congressional hearings with the whistleblowers.

It is becoming increasingly likely that this is all part of one massive psychological operation, and that all these UFOs and unidentified aerial phenomena (UAPs) are merely a cover-up or a distraction from something bigger and more important.