The Mount & Blade series is for sale.
Mount & Blade - there is no reason to purchase this game aside for a couple of mods that were never updated. Avoid this, don't buy the pack that includes it, it is a cruel trick. Warband is basically the upgraded version of this game, with all of its content plus better graphics, multiplayer, and a new faction.
Mount & Blade: Warband - this title is amazing if you like sandbox games and realistic fantasy. There is no magic, but plenty of swords to go around. You start off as a minor adventurer and can grow to lead an army, stand behind one of the warring kings, declare for one of the heirs of a faction and help them come into power, or create your own faction and unite the country under your own banner. It is very addictive if that playstyle appeals to you. The whole time I played this game, I found it somewhat reminiscent of the "A Song of Ice and Fire" series (though obviously not as well-written.)
Mount & Blade: With Fire & Sword - Warband + guns, set on Earth instead of a fictional world. This was... not well-received initially. It was buggy, lacked options, firearms were stupidly overpowered. I regretted buying it when it first came out- I spent just under 100 hours with Warband, I spent less than 5 with this before quitting. It has since been patched, and I've heard it is greatly improved, but I have yet to play it since. Don't get me wrong, there were very good changes- actual quests that didn't feel generic, better trade, a storyline, a different recruitment style, better sieges. If it is as improved as the patch indicated, I would say it is a must-buy. Until I give it a fair try though, it is difficult for me to recommend at the full price. For less than four bucks, though? I say grab it.