My buddy is playing an astromech named 867-5309. So there's that...
Since pretty much everyone seems to do it, let's start a pop culture inspired droid designation name thread.
When he rolled "loyal" and "enthusiastic", refurbishing and reprogramming an ancient Sith war droid, the Tech called it 600D-80Y.
How about, everyone writes the meaning behind the droid names?
Not everyone get it, especially when you from a different cultural background.
This Thread would be so much more fun 
So we ended up naming out B1 battle droid after all. At first we were going to use him for carrying spare weapons around and call him C4-D1 ("Caddy"), which would also be a good name if we used him for handling explosives. As it turned out, he got the name B1-D3 ("Bidet") since he will be tasked with all the dirty jobs...
There is an astromech on my party's ship that has the designation R4-D4, but likes to be called Radar.