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

[Angrboda]

There are several converging lines of evidence which strongly suggest that consciousness arises from physical processes. If this is the case, then it is highly unlikely that it survives the destruction of that process in death, failing some sort of intervention to transfer that process to another physical system.

I had a good summary at one point, but I can't seem to find it. Off the top of my head, some of the lines of evidence are:

1. a priori arguments -- there seems to be no way of reconciling the physical evidence with non-physical mechanisms even in principle; a non-physical mechanism implies dualism and the problem of interaction or communication between obviously physical processes (our senses) and some process or thing separate from the body seems hard to imagine or resolve;
2. Evidence from physical damage: brain damage affects consciousness in ways that are both profound and largely predictable; it's hard to square this with the idea that consciousness isn't physically based;
3. Evidence from drugs; same as 2;
4. Evidence from evolution: many animals show signs of some sort of consciousness suggesting that as brains evolved, so did consciousness; otherwise this seems to require a rather elaborate ad hoc explanation;
5. Evidence from sleep and anesthesia; if consciousness is non-physical, where does it go and how or why does it come back? This is similar to #2 and #3.
6. Evidence from brain studies and imaging; brain activity correlates very strongly with the presence or absence of various features in consciousness. The receiver theory has been suggested in which the brain is just a receiver / transmitter that sends and receives information from a non-physical process. This in addition to the communication problem (e.g. Popper's three worlds) leaves unexplained why so many different areas of the brain seem involved with and correlated with aspects of consciousness. If the brain just transmits and receives information, why is there so much complexity and so many correlations with the thing itself -- consciousness?

I've no doubt missed a few. If I think of them then I'll add them.

If you want to read a good book about physical ideas about consciousness and the philosophical problems with a physicality theory, I'd recommend Neurophilosophy by Patricia Churchland. Written in the 1980s, the neuroscience is a bit dated, but the meat of the book is about how to think about consciousness from a philosophical viewpoint, and the various paradoxes and questions pertaining to the subject. Highly recommended.