Forgot to mention, My dad's house we put limestone. It's nice, but between gravel and limestone. I personally like gravel. The limestone seems to always have slurry to it when wet, which always is on shoes and does track into the house slightly. Maybe Texas doesn't stay wet enough like around here to be a problem.
If money is no object, go concrete. Some around here put a concrete slab in and around the parking area. It helps buffer any tracking of limestone, asphalt, or anything else into the house.
