Everyone else already posted a bunch of my faves, so I'll try to throw in some others.
Being drunk and pissed off about not being able to find his pipe tool, and lapsing in and out of cockney English/regular Boglim speak as he angrily stumbled about in the first apartment. The animated one really condenses it, but the whole thing was great.
Him and Darf's Budweiser passout a thon. The whole thing is magic.
The time he looked up and his gay cowboy hat tilted up and down because of how it was angled against the chair.
Any of the old 1st apartment vids where he'd say something obviously made the fuck up and stutter through it, struggling in vain to sound cool.
Since the NAL lap fart was already mentioned, the whole fucking "your pussy smelled like Wendy's" thing.
Most of the lines from the Respectful Goth Picnic video.
All of the various idiosyncracies, TWU, it is what it is toobs, that's the thing of it, no skin of my shoes, that's the thing slick, bottle clinking with rings, looking into the bottle like a spyglass. GENETIC MTN DEW/Lukraine Cheese! The boy is just endlessly entertaining.
Honestly his original tagline of Sexy Goth Badboy is still fucking solid gold. It was funny when he was an awkward middle school mall goth who looked like your lesbian aunt, and it's just as funny now when he looks like a disabled vietnam vet.
EDIT: Obviously the hair dye vid, but I'd like to suggest whatever old video that GIF of him with a bunch of black lipstick allover his face like black metal corpse paint, with the shitty pentagram on his forehead as a close "lol WTF is on your face" runner up.