A-24 Banshee (Douglas) / F2H Banshee (McDonnell)
AC-47D Spooky (Douglas) / AC-130U Spooky II (Lockheed)
AF Guardian (Grumman) / AH-64E Apache Guardian (McDonnell Douglas)
AT-6 Texan/Harvard (North American) / CT-156 Texan II/Harvard II (Raytheon -Beechcraft)
AV-8 Harrier (McDonnell Douglas) / AV-8B Harrier II (McDonnell Douglas)
C-46 Commando (Curtiss) / H-3 Commando (Sikorsky)
C-47 Skytrain (Douglas) / C-9B Skytrain II (Douglas)
C-74 Globemaster (Douglas) / C-124 Globemaster II (Douglas) / C-17 Globemaster III (McDonnell Douglas)
EP-3E Aries (Lockheed P-3As) / EP-3E Aries II (Lockheed P-3Cs)
F4U Corsair (Vought) / A-7 Corsair II (Ling-Temco-Vought)
F-5C Skoshi Tiger (Northrop) / F-5E Tiger II (Northrop)
F6F Hellcat (Grumman) / 2C3CDZC9FH SRT Hellcat (Dodge)*
F-86 Sabre (North American) / F-100 Super Sabre (North American)
F8U Crusader (Vought) / F8U-2 Crusader II (Vought) / XF8U-3 Crusader III ( Chance Vought)
FH-1 Phantom (McDonnell) / F-4 Phantom II (McDonnell Douglas)
L-2 Grasshopper (Taylorcraft) / L-3 Grasshopper/Defender (Aeronca) / L-4 Grasshopper (Piper) / L-6 Grasshopper (Interstate) / L-13 Grasshopper (Stinson/Convair) -- L-16 Grasshopper (Aeronca)+
P-38 Lightning (Lockheed) / F-35 Lightning II (Lockheed Martin)^
P-47 Thunderbolt (Republic) / A-10 Thunderbolt II (Fairchild-Republic)
P-51 Mustang (North American) / F-82 Twin Mustang (North American)#
P-61 Black Widow (Northrop) / YF-23 Black Widow II (Northrop)
P-70 Nighthawk (Douglas) / F-117 Nighthawk (Lockheed)
PBN-1 Nomad (Consolidated) / H-23 Nomad (Hiller)
* Grumman had a tradition of naming naval fighters with a "cat" theme such as the Hellcat above and the F4F Wildcat. A fun example is the F4F-3S Wildcatfish, which is simply a F4F Wildcat equipped with floats.
+ Not all 3-place Liaison aircraft were known as Grasshoppers: L-5 Sentinel (Stinson); L-8 Cadet (Interstate); L-9 Voyager (Stinson); L-14 Army Cruiser (Piper); L-19 Bird Dog (Cessna) More often that not they were simply called "Maytag Messerschmidts" or the "little green planes."
^ Variants = XP-58 Chain Lightning, P-38M Night Lightning
# Last American piston-engine fighter ordered into production by the United States Air Force.
Missing the Vought O2U Corsair, O4U Corsair, and SBU Corsair (they really liked that name), Lockheed UC-85 Orion and P-3 Orion,
McDonnell Douglas F/A-18 Hornet and F/A-18E/F Super Hornet,
Douglas BTD Destroyer and B-66 Destroyer,
Grumman TBF Avenger and McDonnell Douglas A-12 Avenger II (never flew),
Grumman F11F Tiger and F11F-1 Super Tiger.
F-5A/B/C were officially named "Freedom Fighter", "Skoshi Tiger" was a nickname derived from a combat evaluation program