If you only count living, breathing machines not sitting in museums:
A-7D, A-10A, F-4D, F-15A, F-16A, OV-10A, Avro Vulcan B.Mk2, M60A1
The A-10 impressed me with its enormous size, raised rivets at the back end, and that gargantuan gun that had “Do not rotate-gun will fire” stenciled by the muzzle.
The Vulcan was something I never dreamed of seeing. It was at an open house at Hickam AFB, parked away from the other US aircraft. No one seemed interested in the Vulcan except for this one little kid with a Kodak Instamatic camera with only a dozen shots. Actually I saw a Vulcan twice at Hickam, the first time it had a light grey underside, the second time it had the darker wraparound scheme. Man how I wished I had my digital camera or smartphone! But that was back in 1977 and 1982 I think.
The first time I saw an F-15, the thing that struck me was that the sway braces for the Sparrow missiles were big “C” shaped chunks of metal sticking perpendicular into the airstream.
I’ll remember the F-4’s thick, warm, velvety, oily and stinky black soot from the inside of the exhaust petals. Dad said “don’t do that”, but I just had to run my finger through that gunk!