CBS' Crime Time After Prime Time block in the early to mid 1990s was mentioned a few times in this thread. Given its time slot, it's kind of obvious the production values, etc. would be less than what you'd see in prime time. As I recall, most -- if not all -- of the shows in that block were Canadian imports (or Canadian production companies had a stake in the series). One of my favorites from that era in CBS' late night programming strategy was the Montreal-based "Urban Angel" (1991-1993). You could tell the production was a bit flimsy, but the plot lines, in my opinion, were solid and the cast gelled. It also had one of my all-time favorite theme songs.
Speaking of Canadian-produced series, here's another one I don't believe was mentioned: the teen-targeted sitcom "Hangin' In" (1981-1987). The earnest series focused on the goings on at a teen counseling center and was a launching pad for a number of actors. (Eric McCormack, later of "Will and Grace" is one such actor.) Nickelodeon imported the series here in the U.S. in the late 1980s. In 1990-91, WGN also used reruns of the series on its national signal to cover up programming on the local version that was subject to SyndEx.
Speaking of Canadian-produced series, here's another one I don't believe was mentioned: the teen-targeted sitcom "Hangin' In" (1981-1987). The earnest series focused on the goings on at a teen counseling center and was a launching pad for a number of actors. (Eric McCormack, later of "Will and Grace" is one such actor.) Nickelodeon imported the series here in the U.S. in the late 1980s. In 1990-91, WGN also used reruns of the series on its national signal to cover up programming on the local version that was subject to SyndEx.