Fiddler's Green Sopwith Camel - built this back in high school, almost a decade ago. No clue where it got to, but still have this one pic:
Farside rocket by Mike Hungerford - also built this one in high school - it survived to this day and is sitting on my shelf (comic says "It's time we faced reality my friends - we're not exactly rocket scientists"):
Flying Pig Zen automata:
2003 WRC Subaru Impreza:
Fiddler's Green UH-1 Huey:
Optimus Prime by paperrobots1999 (yes, he transforms):