I need to use a MacBook as my work machine (for a little over three years now), and generally have a strong dislike of the platform. It's just similar enough to Linux to lull me into believing that I kinda know what I'm doing, but just different enough to make me feel incompetent whenever I try to actually do anything nontrivial.

    System Preferences -> General -> Show scroll bars to Always.

I stumbled across this little gem about a year ago, and has been one of the bigger quality-of-life improvements I've found on this machine.