I used to sell on eBay. Now it just is not worth it at all. Even though they have the biggest user base they charge exorbanent fees.
Paypal is a disadvantage because it is owned by eBay. I think it is also required now which must be illegal somehow. Not to mention it is not very secure at all.
http://www.powersellersunite.com/
Bonanzle seems to have become popular pretty quickly...
http://www.powersellersunite.com/auctionsitewatch.php
Are you going to auction your stuff or straight sell it? If you are just selling then I would not bother with eBay at all.
Here is my list of eBay alternatives...
http://ebaysux.yolasite.com