SR-71 is a spy plane. It has no armament what so ever.
Forgotten aircraft:
AH-1 Cobra

Still in service with the USMC as the AH-1 Super Cobra and AH-1 Viper. Replaced by the Apache in Army Service.
F-4 Phantom II

This use to be a common multi-role plane in Navy, USMC, and Airforce service. Retired in the 90's.
F-117

This was the tactical stealth bomber of it's day. Retired in 2008 due the introduction of newer stealth aircraft.
B-2 Spirit

Strategic Stealth bomber, very few produced, doesn't see much action, still in service.
A-6 Intruder

Naval bomber and anti-ship plane. Retired, Prowler variant is still in service.