I'd love episodic X-Files adventure games. Dark, atmospheric, but also hilarious in places. I guess now the TV series is long gone it would be hard, and the fans would gripe about stand-in voices.
Other 'historic' IP's I think would be really fun as episodic adventure games include Thunderbirds / Stingray etc, Dr Who, Young Ones, Blackadder (those may all be too UK-centric) and maybe some of those awful 80s properties like A-Team, Knight Rider, McGyver, if handled with a bit of a nod-and-a-wink etc.
Oh and Hitchhiker's Guide needs a retelling, though what with Douglas Adams stubborn refusal to participate further in that property (or any other), I guess it would be very hard to do...