General Motors states they have the best incentive program for military personnel. Most GM auto incentive programs can be combined with other incentives. If you are a USAA member, you can get an additional $750 off. Register online for more details.
Update: As of 5/16/2014 GM has extended their military discount program to all veterans. Veterans are now eligible to take advantage of the military discount program that was once geared toward active duty & retirees. Click here for more details.
T-Mobile offers 15% Military Discount for active duty and veterans. For veterans, you will need to take copy of your DD-214 in store, complete a corporate discount form and show your ID. If you are in a state where veterans designation is on the drivers license and you have one, you are eligible. Existing customers are also eligible for the discount as well. If you are obtaining new service, the activation fee is waived as well.