I've tried both Blujay & eCrater and have liked them both. Bonus - they're both free! The only thing is that they are both fixed price, no auction feature (I think the auction site to watch will be eBid, though).
Blujay was my favorite except for the fact that they have no inventory control function (so two people could potentially purchase the same item) and their shipping matrix is rather limiting. Still, they are the easiest to use as a seller.
eCrater does have an inventory control function and a better shipping matrix. But they don't allow the use of HTML and they take a bit of a learning curve. Still, a great site.
Both sites are great free sites & get my recommendation. Since I do this as a business, neither site quite met my needs. So, I finally settled on CHShops (my shop there is Animejems):
http://www.chshops.com/
They use the Zen Cart technology and offer everything I've been looking for for only $4.95 a month (that's it - no other fees).
The key to any off eBay site is to promote, promote, promote! I've had sales on all my sites, but I promoted on forums, groups, and other online places. I also still run auctions on eBay (yick!) and include flyers & coupons promoting my new store.
Life off eBay is possible, it just takes a little extra promotional work. But it's worth it.
We'll have to put up lots and lots of cels and sketches for you to buy! 
