I'm a game seller and I will tell you that it goes like this. If you want like 1/3 of the price of the game or less then go to gamestop or do amazon trade in. If you're willing to give it a little time and effort and maybe take a little bit of risk then read below.
Craigslist is best because it has no fees, but it has limitations. It may be impossible to find a buyer if it's not a popular game. The only risk is dealing with a stranger who could try to screw you, but I've never had this happen before. If it's possible i recommend selling on craigslist, if it's a heavy or expensive item I would really recommend craigslist if at all possible. Shipping is expensive and the risks of dealing with buyers online is real. I have had scammers screw me, and I had a PS3 that I sold destroyed in the mail which cost me a lot of money.
Ebay is good for mostly everything, the fees are lower than amazon and you can sell just about anything. I don't recommend doing an auction, do a buy it now price with an option for buyers to make their best offer. Ebay is more friendly to the seller than amazon but there are always risks when dealing with customers and with the post office.
Amazon is generally good too, the fees are higher but you can often get a higher price on amazon. Amazon has very buyer friendly policies that can drive sellers insane, but generally buyers are good and it's not usually a problem. It is easier to navigate amazon for new sellers I think and you can just leave your items on there forever until they sell.
currently playing: Skyward Sword, Mario Sunshine, Xenoblade Chronicles X
