Is there a list of Macs and what is the Last OS they should use for optimal performance

[Lew Zealand]

If you have 2GB or less in your Blackbook, I suggest Snow Leopard as Lion is a real memory hog. I use 10.6.8 in my Early 2006 Blackbook with the max 2GB is it works fine for me. A 7200 RPM drive with the OS in it's own 50GB partition and all my data in the remaining 450GB also helps keep the speed up.