I remember once when I was a teenager turning on the TV at like 2 in the morning on a Saturday and being treated to Adult Swim's Sealab 2021 for the first time. Along with the rest of their line up around 1999-2003. It was fucking weird as shit. But hilarious.
Adult Swims programming from the exact same time you mentioned helped shape me into who I am now, lmao. What an awesome time for TV. I can remember sneaking downstairs to the TV to put on Space Ghost Coast to Coast. I didn't "get it" but I was very aware that I liked that type of dry humor.