oak, NUMERAR Ikea ones. Used the Ikea sealer you get for $5 then applied this beeswax sealer that we reapply every 6mo. http://www.amazon.com/Claphams-Beeswax-870-3008-Finish-8-Ounces/dp/B0012XP7LQ Water just beads right up on the countertops.
Granite Sealer Review: durability, quality, brand comparison and choices for sealing granite, marble and natural stone countertops and floor tile. http://www.countertopspecialty.com/which-granite-sealer-to-use.html