If you are currently using Sedo, Fabulous or Afternic to park your domain names, check out 1Plus.Net. They offer some of the nicest-looking parking pages available. Plus, you can list your domains with them, and there is no commission due if you sell your name through them.
Here are a couple of examples of their parking pages:
You can customize the way your page looks, and even add your own adsense or other advertising code on the page.