I have tried all of them, but have now settled on squirt- about the about the most expensive option, but the only dry lube I've found to survive the wet as well, and also easily manage 100km+ off road epics. Can't be got cheap unfortunately but worth the extra 50% price in terms of longevity. Gold etc I always noticed if it hadn't been lubed in 2 rides.
I usually buy BIG bottles of RNR Blue for the MTB....and put it into a chain cleaner......
In one action, clean and lube chain.
Waste of time cleaning first with "orange" type friendly chain cleaners, cause theyre not friendly to the wallet....
I've used a few different oil based stuff, all works but catches dirt and dust. Picked up some bike milk from at the OHV 24 at easter. This stuff is great, so easy to clean and chain runs quiet. Great also is the chain rings and cassette, no build up. I think that it would give the same chain life. Bees knees as far as I'm concerned.
I go RNR Blue for the MTB- keeps the chain absolutely spotless and is awesome, however needs reapplying a bit more frequently I've found than RNR gold- before most rides I'd put some more on... Gold seemed to attract dirt a lot more, but needed less reapplication- hence why I use it on my commuter.