Another actor whose death didn't cross my radar is Glenn Quinn. Most notably, Quinn portrayed Becky Conner's boyfriend (and eventually husband) Mark Healy on Roseanne.
The Mark Healy character was introduced as the nightmare boyfriend. But, over the years, he devolved into an idiotic caricature of a goofy, working class peon. That demise mirrored the fall of the show itself, which stayed on the air at least 2 years too long and ended with the most nonsensical finale in TV history (Alf's thwarted return to Melmac made more sense.)
Quinn died of a drug overdose in December of 2002. So, K.R.I.P.
Past Retro-bituaries: Mr. Belvedere