Here are a few things Ive got on my list that I currently have in various scripts to gather this information.
Top 10 slowest slowest statements
Missing indexes
Unused indexes review for removal (taking up space)
Login errors (could indicate security issues, or system issues)
Index fragmentation
Top 10 largest tables (might indicate bad process or more likely candidate for purging old data etc)
Can anyone else share some good things to search for?
Some of the above items I would want to look for more frequently than others, so im not sure they would all fit in a single job. It might even be something I roll into an SSIS package and simply run locally on occasion, or automate it and record the data into different logging tables for historical metrics. Not sure yet.