I like to make tamales with pork in a red chili sauce I make from California and New Mexico chile powders with some Chocolate Ibarra added in.
For chicken tamales, I use a green chile sauce made by simmering tomatillos, onions, fresh jalapeno or serrano peppers and garlic. After I cook it, I blend it and add fresh cilantro.
My vegetarian version is simply jalapenos from a can and jack cheese.
My grandmother used to make sweet tamales with a custard. I sure wish I had that recipe!