My personal favorites:
CC - $5 Clearance and 2 for $10 on $20 games glitch
EB - 25% off CAG15/EDGE/SAVER, 85% off used PC games clearance
Gamerush/Blockbuster - Trade 3, Get 1 for $5; Trade 2, Get a new game/pre-order for $30, Trade 3 or more, Get $5 extra per game
TRU - 90% off Green tag clearance, $10 off 2 under $20
CC - $5 Clearance and 2 for $10 on $20 games glitch
EB - 25% off CAG15/EDGE/SAVER, 85% off used PC games clearance
Gamerush/Blockbuster - Trade 3, Get 1 for $5; Trade 2, Get a new game/pre-order for $30, Trade 3 or more, Get $5 extra per game
TRU - 90% off Green tag clearance, $10 off 2 under $20