Spinning Blade Grinder
When most people think of a coffee grinder, they think of a device with a blade that spins around like a blender or food processor. This was certainly my introduction to freshly ground coffee. Spinning blades do not produce very good grind uniformity, but any coffee made with very freshly ground beans will have a lot more life than coffee made with grounds that have been sitting on a shelf. Immersion methods also have more tolerance for imprecise grinds, so this can be a cheap upgrade if you have been brewing factory ground coffee in an immersion method.
Spinning Blade Recommendations:
Mr. Coffee Simple Grind - This is all you need for a spinning blade grinder. Keep it simple.
Kitchen Seal Manual Coffee Grinder - This is a burr grinder, but because of the design, the consistency is similar to a blade grinder. This is a decent backup option you are traveling and want to have something to throw in your suitcase, or if you want to grind fresh while you are camping this could be your solution. Also fits in the Aeropress cavity.