I think my favorite Meet the X videos is the Spy, followed by the Medic and the Pyro. The Heavy, Sniper, Engie are good and funny but too short. I'd love to see more of the Sniper's job, and the Heavy's background story. They have to re-do the Scout, Demoman and maybe the Soldier (though it is very funny).
Hopefully, now that they released the Source Filmmaker thingy, they'll release Continue to Meet X videos
Eh, maybe even some kind of mini-machinima would be cool.