There are several good products on the market. I, persoanlly, use Chamois Butt'r.
While these products are great, if you're experiencing an unusual amount of chafing, you might also consider whether your saddle is right for you, whether your bike is set up properly, and/or whether you need better shorts. While it does take a bit of time to break in your butt to riding, you should ideally be able to ride for moderate distances without much discomfort with a good set up on the bike and the right shorts. I really only need to use chamois cream for longer rides.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher