The guys over on Machinima Versus they have our beloved Guilty Spark pitted against Portal 2’ Wheatly. Now while I have played both games, I believe that Guilty Spark would demolish not only Wheatly, but GLaDOS as well. While both AIs might be tethered to their primary objective. Guilty Spark is able to think outside of his programming in an attempt to achieve his goal of keeping The Flood from spreading, no matter the cost.
At any rate, follow the link and vote: