You should try on a big registrar like GoDaddy.com (lot of exposure) or an a dedicated aftermarket site like Sedo.com

There is not a "best place", many sites run their own marketplace, the biggest ones are:

• Sedo (http://sedo.com)
• Afternic (http://www.afternic.com/)

A good option is via big registrars with a lot of traffic like GoDaddy.

Obviously you can sumbit your domains to multiple services at once to get more chances an interested buyers sees them.

Hope this helps.

Hi,

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BK