Looks like I'm drinking alone, so I'll add another couple of recent dark beer experiments to the list if only for my own self-amusement
From Coquitlam's Mariner brewing, their Night Sky mocha stout:
I found this one a bit like the Andina one reviewed above, in that it lacks the body I'd prefer in a stout. Curiously, it also isn't mocha-y as I would have expected, with both coffee and chocolate being less pronounced than I'd imagine. Combine that with the thinness of the beer, and I'd say it's no better than ordinary. A better - and completely different - beer from this brewery is their Venture Blueberry Sour, which works really well as a summer beer.
One more (which came in a care package from some non-dark-beer-drinking friends) is Driftwood's Black Stone porter:
This was much better. If you went to a bar and their beer list had one that just said "Porter" with no other description, this is the beer you would expect/hope to get. No messing around with any experimentation, just a classic porter in every way, and richer than even some of the stouts above. Definitely recommended if you like porters or stouts.
Last dark beer for today, Hearthstone brewing's chocolate milk stout.
This one is a beauty. Understated, but a great example of exactly what it's designed to be. Really nice texture, sufficiently chocolatey, and surprisingly sessionable. It's not at the level of Old Yale's Irish Imperial or even Sasquatch stouts, but it's not that far behind and may be more approachable than either OY brew.
A couple of other non-dark beers I tried at the dawn of self-isolation are House of Funk's carrot saison (which works as well as it sounds it would, i.e., not so much) and Chaka Khan sour IPA (which works much better than it sounds like it would).
This is a highly experimental brewery, and one of my favourites to do tastings at for that reason. If you find yourself in Vancouver once travel is cool again, hop a boat to North Vancouver and check this one out, which in my view is the best - or at least most interesting - of the now dozenish breweries in the North Shore's brew district.