[ If you're not into reading why I find git history useful, you may jump right into the command-line coolness! ]
I love reading git logs! First, because it reveals the people and processes behind software. Software is not just a bunch of code that works (or more commonly, doesn't work...) - it's also a bunch of people crafting something together for a long time. Not only adding features and fixing bugs, but they also refactor, do dirty tasks and ugly workarounds, explaining their motives in the commit messages.
A second, more concrete reason - quick access to git history helps me make better software. It helps me find out when and how exactly a bug was introduced, learn whom to talk to about a certain change or code, or simply find a desired code snippet in a huge repository - even if it was already deleted. Am I stating the obvious here? I guess so! but I do believe that sometimes this tool is underestimated and underused.