It should be something -everyone- is familiar with. Few people are familiar with Ghostbusters. Even fewer with Halo.

The host (Lenny) won't be able to write a story if he is not familiar with Ghostbusters or Halo.
Lord of the Rings is good. There's lots of famous roles (for both sides) as well as an obvious good vs bad (hobbits vs orcs).
Star Wars is good. Lost of famous roles, rebel alliance vs stormtroopers.
Lost is okay (survivors vs The Others), but it's not known by everyone.
Metal Gear Solid is bad. It's not known by everyone.
Paper Mario is okay, but very similar to last game.
Street Fighter is bad. It's full of individual roles and unclear story. Plus, not everyone knows about it any deeper than than just the names of the main characters.
Girls is okay.
Pokemon is already reserved.
So LoTR, Star Wars or Girls seem like the only sensible options to me.