Dwarves; we all know them well: short, stout, bearded folk of the underground, excellent warriors and miners, oft with values strongly associated with those of the romanticised vikings. Although this is a picture we can all relate to and it bears the advantage of ease introducing the concept to newcomers, it gets old and boring with time.
There have been many excellent variants geared toward making them more interesting (e.g. ASE, Red Tide, Devil's in the Details, etc.); hopefully, the compilation of ideas below may be useful for some people and live up to the standards set forth by the aforementioned examples.