For instance, at the Cupertino Apple Store opening event that happened to be around the launch of Mac OS X 10.2 ('Jaguar') I remember saying to Steve Jobs, rather snarkily, 'It's finally really good.'[1] That's because it felt like we had finally turned a corner and gotten an OS that wasn't this shiny, 'lickable' half-finished proof-of-concept draft of an operating system. It proved we weren't insane for buying into Apple's lofty promised and developing for Mac OS X. So I probably loved that release the most. But of course, wouldn't run it today even if it ran on modern hardware.
But 10.6 is also well-loved, as the numbers above show. It is rock-solid stable, and I still run my OS X-based servers on 10.6 (in VMWare VMs). Company git servers, non-public facing IMAP archive servers, customer support systems, whatnot... all run 10.6.8, and have for years.
As an end user (by which I mean software developer, mostly Mac, with some iOS and web stuff) I run 10.8, but I still find it really irritating and like 10.7 better. There's so much annoying crap in 10.8, both showstopping bugs and UI changes aimed at the lower-knowledge average-Walmart-shopper tier of computer user, that it gets in my way more than it helps me.
But we've already discussed that stuff on this forum many times[2], so I won't rehash it here. I'll just say that so far, 10.8 has made me love it less, not more, than 10.7, so that is what I picked above. (And currently, it looks like I am the only one to have done so.)
Also, a real lion would kick a mountain lion's ass.
[1]: Jobs handled my snarky comment the same impressive way he used to handle irate shareholders at the annual meeting: he acknlowedged but implicit criticism but didn't validate it, he accepted and accentuated the praise, and then he invited the people listening to him to join him in feeling good about all the awesome things Apple was doing.
He looked at me and said, 'You know what? You're right, it is finally really good.' He glanced around to include the other people standing around us in the conversation. 'Maybe we should use that in the ads. Mac OS X 10.2: it's FINALLY really good.' Polite laughter ensued, and then he went on to describe a couple of his favorite new features and how they were going to change the world.
I guess apple knows best though. Thanks for making it easier for me despite the part where it seems harder. You sure do know so much! /sarcasm on that last paragraph.
While a buggy turd, 10.0, was amazing at the time and blew windows out of the water. It was phenomenal by comparison.
In the end I ended up voting for 10.8 because it works damn well-- was a painless upgrade process, even with all my dev tool installed. That has definitely not always been the case.
This attitude reminds me of Mel Gilbson's house in "Conspiracy Theory" -- with locks on the fridge and on the food containers inside it and all.
Not to mention that even in Mountain Lion you don't have to "deal with the silly Mac App Store" if you don't want to. Just use it to get the core OS updates, and download all your apps from their original sources.
The UI in 10.8 is far too flat for my tastes. In this era of advanced graphical processing and processing, I would expect the trend to go the opposite way.
Oh well; guess we have to do what Apple tells us we want; otherwise we'd have to go to Linux and break compatibility with a LOT of apps.