Normal is my favorite Pokemon type. For one it's a very versatile type. Many normal type Pokemon can learn moves from a wide array of other types (Ratatta being one example) and although they're fiendishly weak against fighting types, cannot damage ghost types, and are only half effective against steel, and rock types they are still very nice team filler if you can't figure out what your sixth Pokemon will be. ^^;;
Another reason is that, aside from being cute, most normal types can be incredibly sexy without even anthropomorphism. Lopunny, Miltank, and Tauros are great examples of this. Grass comes in second in my list of favorite Pokemon types.