Mount & Blade is one of my favorite games on PC. It's an open-ended world that allows just about anything. If you want to be a traveling merchant, a mercenary for hire, a thieving bandit king, or the champion general of an entire kingdom, it's probably possible.
On top of its freestyle gameplay, it's also very friendly to mods. Better yet, it's easy to have multiple mods installed with Mount & Blade. I've rounded up a few of the most interesting ones here for you to try out. Feel free to install them all, but just expect to stay up until 3:00am tonight.