No offence, but you guys are getting carried away.
Usually GMG has far superior prices on steam games if you are just willing to wait and pick them up here and there. Granted, I've bought a good amount of games on steam in the last year.
You will seriously never get through your backlog. I would recommend only buying games at 75% off that are already $10 or less. These games will likely never go down in price. Don't drop lots of money on relatively new games if you have a backlog. They will drop fast and also there is a good chance GMG will have a sale on them with better coupons.
As far as wishlists go, here is mine (mortal combat I'll get far into the future, most likely)