I think the episode I've enjoyed the most thus far in my Rocko watchthrough is Cruisin' - it starts off slow but once it hits the second segment (it's a full-length episode) it is incredible. Perfectly encapsulates the visual surrealism and heart that keeps me watching this show (there's one moment where the juxtaposition of a quick switch from sincerity to absurdity brought EarthBound of all things to mind, you'll know which scene if you've seen the episode), and has a pretty well-structured plot for a show that usually opts for stringing together gags out of a single theme or location (not that there's anything wrong with that of course). While it's possible my mind will be changed over the next 2 and a half seasons, this is absolutely what I'd consider the show's "Band Geeks" moment for now.
Another thought about this show: the whole idea of this being "an adult cartoon that aired on a kids' channel" is way overblown. There have been some "Wow! They got away with that?" moments for me, some of which have been full episodes like the deportion sham marriage episode and the infamous infidelity episode, but those moments are very few and far between - rather than being a sign of "aiming for the wrong audience", I feel that the show's protagonists being adults is its gimmick, and little to none of the stories thus far could've worked with kid or ambigiously-aged protagonists just as none of the Rugrats stories would work with school-attending 8-year-olds or none of Jimmy Neutron's stories would've worked with a run-of-the-mill above-average-IQ teacher's pet with no invention skills
Ironically he had Jonesy placed above Master Chief