Steam is currently having a sale on all the Mount & Blade games (With the exception of the new Multiplayer only, Musket expansion for Warband) The games are wicked cheap and i've put hundreds of hours into the series, you really should pick them up and try them out. If you like melee combat that feels good, a gigantic open world with plenty of stuff to do, 64-120 player castle sieges, tons of mods for everything from world war 2 combat, to horde mode, and deep RPG mechanics, this is the game for you.
I recommend Mount and Blade:Warband as it's the best in the series and built heavily on the first game. if you find you love that it's worth going for Fire and the Sword as that does some different things (Post-Medieval setting, more of a story focus.) with the mechanics. All the games run like a dream on pretty much anything you got.