Talking about Mount and Blade original mods, there are some decent ones, such as 1805 Beta 1 and 1805 II which I helped out making. Custom Settlements is dead, and incomplete, but still fun. 1866, the Western mod is still kick ass.
For Warband, I mainly play Floris Mod pack, Blue Blood, Europe 1257, Brytenwalda, and Native/NW of course!