I love this collection!! I'm working towards something similar myself, but have a long way to go.
I may have missed it, but what's the story behind your C-3PO? What castings did you use, and did you have it vacuum metalized somewhere?
I agree, your R2 is one of the best I've seen. I saw pictures of yours a few years ago on the builders forum, and had no idea you had such a nice collection. My aluminum R2 has a long way to go, but I really like the 2-legged look of yours. If mine turns out that good, I'll be very pleased!!
Also, love your ANH Vader. Have you considered the Tarkin bust that was posted on the forum several weeks ago? That would look very cool in your room. :love