I agree with others in saying lon live Mac OS 10.6.8. With yearly Mac OS updates the new Mac OSes will never be as good or as solid of a change os OS 10.6.8 was.
If you want still use Snow Leo - you can. As i am. I am sticking with SL by choice on my MBPro. It is latest 17" model (Late 2011, 2.5 QC i7, 16 GB ram, 120 GB SSD + 750 GB HDD, Antiglare) which I bought last summer when I realized that is the last MacBook in my favorite size, with large, matte screen, and that such will not be. It was sold with Lion but according to Machine Profile info - minimum system req. is 10.6.6!
It is still in the store
For me - SL is still primary system for working machines; fast, stable, giving the assurance that nothing will break me in the middle of work.
I have bought ML too, installed on other HD to the test, but unfortunately it is not as fast as SL.
One future (for me) is missing - iCloud. I would like to be able to use this solution to sync with my iOS devices.