Best place to sell/trade physical games?

Do it on eBay,

Maybe a collector will be interested in the games if your games is in good condition etc.

Ebay is your best bet. There is no store that won't rip you off. On Ebay you can get the most money for physical games. What you have to do is sort by "Buy it now" and then click "lowest to highest" and find the cheapest item that is in similar condition to yours and list yours for 1 cent cheaper so it shows up first. When you list it include the buy it now option instead of bidding. It'll sell faster that way. I always do this.

I'd still put them on Ebay. The slower returns are worth it for the extra money you get. I went to a fancy retro games store in town with outrageous prices and they tried to offer me 50 cents for a game because it was 'incomplete' (missing box). Went home and sold it on Ebay for 10 bucks.

Craigslist is free, can't hurt to try putting an ad.

I've been in this position before.

Gamestop is generally terrible, unless you can time it with the right promotion and have the right games. Otherwise, you'll get pennies on the dollar.

I used to use Goosex for a long, long time, but it went downhill, sold to new buyers, briefly got a bit better, then tanked and crashed completely.
Before Goosex crashed and burned, a user created a new site that functioned similar and had a great community going while the owner built up the site and the database (VGFive), only to have the owner sell his site to the new owners of Goosex, which meant that inevitably, it crashed and burned when Goosex did.

99Gamers sprung up when Goosex was first circling the drain and they saw a market for all of the dissatisfied users. I haven't done a whole lot of trading there (just buying so far), but I've had all good experiences. The big downside is that you don't get real money. You get paid in virtual currency for use on the site, so its good if you want to trade your stuff for other games, but bad if you want money back.

I've sold things on eBay without any issues, but as someone else mentioned, document condition and tracking to help protect yourself. Ebayer buyers are notorious for trying to rip sellers off by saying things didn't arrive or where missing things.

For me, I think Amazon works the best if you want actual money back. It takes a little while for the money to clear and deposit in your account, but you'll be selling to a huge market and you can set whatever price you feel is appropriate. I sold off a number of TurboGrafix16 and Turbo Duo games on there, after I discovered some of the ones I owned were worth a chunk of money ($20-70 each). Considering they can all be played on my Wii or Steam, I didn't see a reason to hang on to them.

But, for all of these methods, you'll have to deal with shipping, and the resulting costs. For large items, that can completely negate any monetary value you would have gained. But if you want more shipping advice, I have plenty to offer.

Also try putting up ads on craigslist or if you live in canada use kijiji.