Not very original, but we named our first one "Rosie". We just bought a second one for upstairs, which we will probably name "Robbie" (also not very original).
It is our sincere hope that they will take a liking to each other and produce a couple of little Vroombas to clean our car interiors.
"Do you want me to sit in the corner and rust, or just fall apart where I'm standing?"
- Marvin the Paranoid Android (and our old upright vacuum cleaner)