When a Titan pissed off a Warmind and a few days later it decided to crash land a Warsat on the Titan. Always made me chuckle. Oh, and there are a few Cabal reports you can read about the Guardians. One shows a list of excursions, that repeatedly failed, to kill a fireteam. The description of the guardians throughout it is pretty funny, shows them dancing and riding sparrows and such. Oh, and there's another where someone comments at how weird it is to see guardians dancing without any sort of music at all. He says that guardians brains must be fried to some extent.