I like Amazon the most, but it is really only good for things that are well described by the product description that's already up. So if you have something that's broken or has a glitch, it's hard to really describe it or show your own picture. But for things that still work or that just have cosmetic problems, you can't beat selling on Amazon for ease of use. For example, I'm selling a bunch of tech stuff this week, and here's what I'm going to do with it:
Casio digital camera, worth less than $10 on ebay and works intermittently --> Freecycle
2nd Gen Ipod Touch, seems to work fine, some scratches -->$45 on Amazon
1st gen Ipod Touch with lots of problems --> $20 for parts on ebay
Dell E1505 -->~$100 on Ebay since there's no Amazon product page that matches the one I have
Logitech Z2300 speakers that I repaired by splicing the cables --> $100 on ebay, though I'll probably try Amazon first
Dell Inspiron 1100 --> $50? on ebay
Total I hope to get: $315 before seller fees
Craigslist is a hassle for me because it means talking to/dealing with people on the phone or in person, so I use is as a last resort. It's good if I have something too big to ship or something I really need to get rid of for free (it reaches a wider audience than Freecycle, but there's more spam).