Don't get confused by the title of the thread, I LOVE telltale. It was a childhood dream come true to have Sam & Max return and they introduced me to the world of Homestar runner. Wallace & Gromit just came out, another old favorite of mine, and it turned out pretty well too. The thing in common with all these (plus Bone which I've only tried the demos of) is that they are all based on comics/shows.
Telltale has proven that they are great at mimicking existing art styles and expanding the licenses' world. What I would like to see as their next project (they seem to be pretty busy now though ;) ) would be to try and create a brand new adventure game. Kinda like how lucasarts branched out and made games like full throttle and the dig along with the rest of their titles. Something that isn't based on some existing universe and instead creates an all new one.