Justin, I get the itch to play Baldur's Gate and BGII once every few years. I'm so happy to learn that there is a way to play the whole series through in the BGII engine! Baldur's Gate is a fantastic game, and in certain ways, it's actually better than the second. But there's no denying that the engine for the second is darn pretty and adds a whole lot of excellent storytelling.
Susan succeeded in getting me into Doctor Who a few weeks back, and it's safe to say that I'm a convert. For me, I absolutely love the fact that the Doctor solves all of his problems without violence. Don't get me wrong: I absolutely love a good fight scene, and have no problem with violence in books, TV shows, movies, or games. But there are a hundred good shows where characters resolve their conflicts by fighting. It's great to see one where intelligence, cleverness, and diplomacy wins over brute force, zealotry, and violence every time. It'd be nice if real life worked like that.
The five games are a tough call. I'd definitely have to think this one over for a few hours (or days). Since you guys didn't discuss strategy games too much, I would suggest either Starcraft or Age of Mythology. While Starcraft is better from a mechanical standpoint, Age of Mythology is excellently designed, and has a TON of information about the cultures and beliefs of antiquity. If you're trying to reconstruct human civilization, that could be very useful.
Also, Paul, congrats on your first podcast! I expect great things from you.