Individual buyers would most likely get you the most money, but if you want the best "Effort:Return" ratio, I would make us of Amazon's Fulfillment service, more specifically, their Easy Sell service. Just set the price, fill out the info blurb, set the condition, and send it to them. There are a decent amount of fees, about 20% in all, but you can just sit back and wait for the games to sell.
To use their Easy Sell service, the games have to have a bar code of some sort (So generally you want them to be in the original case) so if you have a bunch of stuff that is disc only are carts, you would have to do the slightly more effort required task of labeling the items your self. This consists of...
0. Setting up the account (Not hard)
1. Get some sheets of 30 1" x 2 5/8" labels
2. Downloading the Amazon Inventory Upload Spreadsheet
3. Looking up the ASIN of the number of each item (List on the item page)
4. Putting it into the spread sheet and filling out the rest of the info
5. Pushing the upload inventory button in the spread sheet
6. Making a shipment of the stuff you are going to be selling
7. Putting the labels onto the items
8. Putting the items into a box with a provided packing slip
9. Measuring and weighing said box
10. Brining the box to a UPS mail center and handing it to the peoples.
Its not hard, but the labels are a tad pricey and it can take an hour or two to get everything finished depending on what you have.
