If in the same area, from what I've eaten I prefer mule deer. Both are good, and if seasoned and grilled I probably couldn't tell you the difference, depending on what I had to drink while burning it. But I can tell you hands down, when I pull the meat from the freezer and thaw/unwrap it the last couple whitetails I had smelled far far more gamey.
I love venison, but I hate the gamey smell.
