Previous incarnations of this list seem to have been useful, but are not aging well. This list focusses on the Mac, rather than iOS (I have another page of iOS recommendations, if that’s your thing). If you need such things, you likely already know about them. I’ve attempted to avoid listing the more standard stuff, like iTunes or commercial software like Photoshop (or many games).
Other recommendations are targeted at “switchers” from Windows who might be looking for replacements for specific software on that platform. Some entries might be more obscure “best of breed” solutions for problems that you might have (even if I might not). Most of these recommendations are based on my own use of the software. It is intended for people who have just started using a Mac.
To save time the next time someone asks me, I put together this list of Mac OS X software.