Mobius' Robot B-9 from TV's "Lost in Space":

Despite the fact that there are relatively few parts , this model was a pain in the ass to build. It was pretty clearly made from a VERY old mold and the parts that made up the arms did not fit well together at all. The instructions were also shit and I didn't end up using them. Fortunately, the model was simple and it was pretty clear where things went from the picture on the box. That being said, I really enjoyed this build because of the painting. This one required extensive masking. Which is very time consuming. even though I used rattle cans, it came out VERY well. (For me anyways).
Revell's reissued Battlestar Galactica Viper:


So this one was a joy to build from beginning to end. It is also a pretty simple model to build. All the pieces went together well. This one is awesome more for the painting than the building. I'm about halfway done painting this one. I have more weathering and detail work to complete. I'll eventually get around to finishing it. However, it's far along enough now to call it "done" if I really wanted too. I didn't end up using many of the included stickers. For example, all of the stripes on the model are included in the sticker sheet. I Figured those would turn out looking really lame so I hand painted those on. It made weathering the stripes a breeze. I did use the Galactica insignias and the pilots name stickers.
There you....I'm sure you were totally enthralled.