What do you prefer and why?
I'm still working on the first bottle I bought a month or so back and can't remember the name. It's just oil though. Nothing flash. I remember back in the eighties, they were experimenting with spray on waxes and some of them were brilliant. Some were horrid. There were thick oils and thin oils and oils that crawled out the bottle, lovingly caressed every link and roller in the chain then fought to repel every piece of grit that dared approach the chain.
The absolutely most wonderful product I found was in a 2 dollar shop back in the eighties. Spray can. Purported to clean and lubricate your chain. Yeah. Right. It was darned near all solvent but by cripes it did a good job cleaning your chain (the pressure helped), wipe with a rag and then a squirt of oil. Great during a very wet winter (I was cleaning the chain every couple of days that year). Sadly, being the sort of shop it was, once I'd bought all their stock they stopped stocking it

But that was then and this is now.
Chain care and protection.
What do you use and how?
(at the moment, I'm using the 'think about it during the ride, forget about it at home' method

Richard