After a certain age people stop asking you what your favorite dinosaur is, and I think that's sad.
My current one's the Anchiornis, because it's in the same clade as birds so it's in their family tree, and it really looks like a prototype of a bird. It had 4 wings for example, but it already looked very birb-y:
(Figured I'd just turn an earlier comment into an actual post because why not)
Nah, it's the first one because that's exactly where we decided to draw the line. Birds have to start somewhere, so why not with archaeopteryx? So it will never change no matter what other species we find.