MacOS 9.1 Update -> MacOS 9.2.1 Update -> MacOS 9.2.2 Update If your Mac system restore leaves you in the V9.0 realm, it can be patched as follows: So, you are half way there, with only V9.1, V9.2, V9.2.1, and V9.2.2 to consider.
You can probably rule out V9.0, V9.02, V9.03, and V9.04 for stability issues and the lack of enhancements. However, I can tell you from personal experience that it is best to do some research after you decide upon your favorite application(s). In general, many users have favored the very last revision, Mac OS 9.2.2 as the most stable and preferred version. Unfortunately, there has always been a heated debate on which Mac OS 9 version to install. Below you will find some general background info:
