Taking inspiration from chinothegeeko's thread listing all the known Target exclusives, here is one for Walmart's. Every little bit of help in filling this out would be very much appreciated.
City
3222 - Helicopter and Limousine $29.99 (2010)
3648 - Police Chase $24.99 (2011)
4206-2 - Recycling Truck $29.99 (2012)
4429 - Helicopter Rescue $59.99 (2012)
60005 - Fire Boat $29.99 (2013)
60048 - Police Dog Unit $29.99 (2014)
Star Wars
7778 - Midi-scale Millennium Falcon $39.99 (2009)