My favourite airplanes are the F-104, the F-4, and the F-16 (in original form). Not really a good plane in a capability sense, the F-104 is the "coolest" looking plane ever. The F-4 is, over 40 years after it came out, a really capable, massively powerful plane. One of the few that was operated by the Navy, Air Force, and Marines. I like the original form of the F-16, in its air superiority/dogfighter form. I still don't think it makes a good ground attack fighter, but that's what they have it doing now.
I like the XB-70 because of the way it pointed to the future. A late 1950s design (one of the most forward looking planes ever, as we still do not have any Mach 3 capable aircraft in regular service in any air force, 40 years later), it did bring some new concepts into aerospace engineering. Things like riding the compression wave to improve high speed fuel usage (by dropping the tips of the wings down so they were vertical), the all out speed, the use of the forward "canards" (the little wings near the nose that perform a lot of the functions of a conventional planes tail). The engine placement was also new for the time, but would later be adopted for the Russian Tu-144 (their supersonic transport plane) and in a modified form, the Concorde. The base technologies were all known of course. It isn't the base technologies that made the XB-70 special, it was how they were combined and mixed together to come up with something new. And the other part is, the XB-70 was, and is, an amazingly beautiful airplane. Even if the XB-70 were to come out today, it would still look modern. And despite the fame of Kelly Johnson and the Lockheed "skunk works", some of the most advanced airplanes of the time were NOT from there. The XB-70, and the F-107 Rapier/F-108, the Mig-25, and even our own CF-105 were all advanced aircraft designs/aerodynamics, and had nothing to do with Kelly Johnson. In fact, it could be said that the F-104, and possibly the U-2 were both Kelly Johnson designed, and were failures in some regard. Some of the stuff that was being done at North American Aviation, General Dynamics, and Grumman (with the later F-14) were as advanced, if not more so, than what Kelly Johnson was doing.
I think what they did to the B-1 is sort of sad. They came up with a real heavy bomber that was supersonic, then cut it back to be subsonic. Like many other aircraft projects, the politics got involved, and messed up a good design for the worse.
The Ferrari is long gone. It was going to be a fairly big model. You are right, it was very expensive at the time, and would have been a real show piece if I had ever finished it. The impatience of youth, I guess.
Kostas