I think beyond a shadow of a doubt this thread will be mostly military aircraft - so far it has been anyway. Which there is nothing wrong with that at all.
Here's one that quickly became a favorite of mine because of the Medal of Honor series: Horten Ho-229
One of my favorite commercial jets - It's a complete same all were taken out of service: Concorde
Out of the bomber class aircraft, this one is probably my second favorite - North American XB-70 Valkyrie
My third most favorite out of the bomber class - B-2 Stealth Bomber
My favorite of the bomber class - Tupolev Tu-160
This plane can rain death of any type - be it biological, nuclear or conventional, from 40,000 feet or more, without endangering the crew in any way. By the time you knew this plane was in the sky, you'd be dead already, as it is capable of carrying some of the longest range weaponry there is. This plane is comparable to the Rockwell B-1a Lancer prototype, which unfortunately never saw the light of day. The B-1b Lancer is used today. It is faster and more agile than some of the advanced fighter jets out there.
That's some more of mine. I have so many, it'd probably take up two or three whole pages on CF, and quite frankly, even though I would love to do something like that, I know I can't.