I have a 2006 iMac currently running Snow Leopard. So I ask, Is it worth upgrading to Lion? Snow Leopard is Apple's greatest version of OS X followed by Tiger. They run smooth on even the worst machines. Specs: 17" Core 2 Duo 2ghz 1GB Ram Radeon X1600 128mb I cleaned it up ready to reformat because there was 7 years of junk on it. There are still tons of random folders and dead programs so a proper reformat needs to be done regardless of my decision.