I honestly can't decide. I seem to have a different favourite character for every series of RvB. Omega is consistently high on the list and the scene where he meets Andy the bomb had me in stitches.
Omega-Thank you for introducing me to your bowling ball...Hello, bowling ball.
Andy-Actually, I'm a bomb.
Omega-It can talk?
Andy-Why is that the first thing everyone says to me?
Omega-A talking bomb you say? I could have use for you in my organization.
Church-I should mention that Andy was designed to blow up and kill you.
Omega-...Well, this is awkward.
Andy-KABOOM!
Omega-Satans bunions!