We use the ones from
www.piddlepads.com and have been very pleased! We purchased a dozen about 15 months ago and they have been a wonderful investment!! (We purchased the plaid print and they look a little nicer.)
We use the Oxy Solution for pets along with Tide everytime we wash them to help clear out the urine smells. We normally do not dry them....we let them air dry outside in the sun...which I think also helps "refresh" them.
They are a backup option for our girls....as when we are home they use the doggie door to go outside to their little potty area....so ours do not get lots of daily use.