They are mostly games I just buy and trade back in. Right now this weekend, they bumped up trade in values AND have a promotion for 50% more trade in credit when you purchase the Doom and the Uncharted 4 game. I usually just buy the game, ask for a gift receipt, and return it back on my gift card. For instance, right now the Rise of the Tomb Raider for the 360 is $20 at
Best Buy with their gamers club unlocked membership, and you can trade it back into gamestop for $40 with the promos. Same with NBA Live 16 (bought at Fry's for $12.99 and traded it back for $33). Some of the games I traded in yesterday are from my own collection that I just don't play anymore too.
Also... I was at the mall today, went to the Gamestop I normally don't frequent and checked for Ebay cards. They didn't have any, so I asked the employee If I could consolidate my gift cards because "it's leaving an indent in my wallet"

The employee combined the rest of my gift cards onto one. She basically bought 1 $500 gift card with my 5 $100 gift cards and it went through just fine. I was asking her a bit more about the gift cards and she said you can put a max of $500 on a gift card AND you can purchase them digitally and physically online. I haven't yet checked if the website GC > GC purchase works, but it's a great option if you want to stay low key/don't want to look weird swiping 5 gift cards at the register.
Okay so this is confusing me, lol. You get more money than you paid for them when trading in? Thanks for the explanation! It looks interesting, but I don't have enough game knowledge to do this right, I'm sure! Looks like it could be good, if you did have that knowledge, as you sound like you do!
Interesting about the GS gc's. So, are you talking about turning say, 5 $100 gc's into 1 $500 card online possibly, either egc's or physical? At first read, I was thinking maybe you were thinking of buying Ebay gc's online, but reading again, not sure that's what you meant. It would be pretty cool to be able to buy the ebay gc's there at GS online with GS gc's to avoid that in person visit. That would be really great then! But, even putting the small gc's into a larger one for use in store would be nice, too.
ETA: I looked at GS, and see you can purchase a GS egc(takes up to 48 for delivery) or physical card(takes 1-2 weeks to get), limit of $500 on one card. But, interesting, my auto ebates thingy popped up showing 2.5% for GS, though I don't know if it works for buying GS gc's with GS gc's, but that would be pretty cool then! Can't try it, converted the last of my cards for the moment.
So, I did go to a different GS than usual tonight, in a far western suburb of Chicago. Went in, with my three young nephews, and with my same attitude, just picking up the ebay gc from the the rack and taking it to the register, with friendly chit chat as the guy asked if I needed help. Just handed him the card and said I wanted to put $500 on it, and it he rang it up and I put my $100 gc's in, one at a time. Asked if I had rewards, but just said no. He mentioned something about gift buying and I said yeah, it's graduation time, and bday's in my brother's family(he has 7 kids, lol), and so I was getting ready and he laughed, saying good idea. So, again, another successful GS converting run, and at a different place than my usual. I was a bit surprised because during my first go round a couple months ago, I called and they weren't sure of using gc's to purchase the ebay cards, or over $300. I had never ended up going there as my local GS goes so great. I think the positive attitude definitely helps!