Originally Posted by Scarlet-Devil
Something set in Planescape could be ridiculously mega awesome. It would also be an excellent setting if you did want the 'modern teenagers get sucked from Earth into fantasy world' thing; then it could revolve around the characters trying to find the right portal back home (from Sigil).
This. Though I would rather the characters were 20somethings rather than teenagers. Unless the show was going to be a gritty Broken Aesop where the teenagers adventure in D&D world when they should be going through high school or early college, then they come back to Earth only to find that they've missed their formative years, have no credentials, and are stuck with dead-end careers, social maladjustment, and generally not having a future, so they end up going back to Planescape because it's the only world where they have a chance of surviving anymore. (Whereas if the characters are 20somethings, you can skip that first part and the whole thing is much more hopeful, because instead of their loserishness being their own damn fault, it's just the fact that they washed out of society the same way real people do all the time, and so finding a portal elsewhere becomes lucky instead of kinda pathetic.)