Half-Life may work - the universe is big enough, and the original series are centered only around Gordon Freeman, Alyx Vance, Adrian Shephard and Barney Calhoun. Telltale could show us something about 7 hours war, for example. The problem is though that it may end up being similar to The Walking Dead, because the general idea is similar - something breaks out - people are trying to survive.
Star Wars is totally possible - you can make up anything about anyone pretty much in any time period.
I also really like "The Sopranos" kind of idea, makes perfect sense with usual Telltale mechanics.
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