Expanding on their service where you can trade in games online, Best Buy is now expanding this service to their stores as well.  Gamers looking to unload previously played games can begin trading them in store beginning 08/29/10.  If you hit the stores this weekend, you can get an extra $20 dollar Best Buy card in addition to your trade in.  According to the press release it indicates this $20 bonus is on over 100 top titles, but we can’t seem to locate that list.    You can visit their website here to find a participating store in your area and to check out more details.