Raw dairy products can be difficult to find depending on your location. Here in the Bay Area, I know Organic Pastures makes a raw butter in a tub, which can be bought at Falletti Foods in San Francisco. If this isn't available, I'd say the Straus or Organic Valley brands are second best.
Organic Valley Pasture Butter is produced seasonally but I can usually find it year round. It tastes great and is healthy, too, because of the high level of omega-3's etc. from the milk from pasture-grazing cows.