Best place to sell a smartphone? Ebay, Amazon, other?

What's the best place to sell a used device? I've got an HTC Titan in perfect condition I'm looking to sell, and a friend who is into tech was wondering this as well as he has a device or two he wants to unload (Lumia 710 for one). He's heard that Amazon is pretty good, but I always though eBay was the best for this type of thing.

Amazon, eBay, phone forums, etc? Craigslist seems a good way to sell quick, but at a lower price, eBay should get a better price but longer time to wait for it.

I'll be including a couple quality cases, all original materials/box and phone in 10/10 condition. My eBay feedback is all positive but pretty small as it's between 10-20 now after being on there since 2005ish.