[Serious] What is the current best scientific evidence we have that shows that consciousness...

[Nanny]

I think the real issue with explaining consciousness is how, as a physical phenomena, it appears so different from other physical phenomena.  It appears non-physical, more like an abstract.

"Consciousness is a being, the nature of which is to be conscious of the nothingness of its being." - Sartre

Consciousness exists but in so doing it is aware that it is not physically there. Consciousness is a process of filtering stimuli and, as others note, is affected by chemicals (e.g. drugs, neurotransmitters, disease). It's the narrative-creator that creates our perception and story of the world. There's a symphony of science piece from years ago that discusses how information is fed to the brain from our sensory systems and "explodes in a collage" of experience.

Ode to the brain:
https://www.youtube.com/watch?v=JB7jSFeVz1U