I think with the Stolen Earth, however much I knew about Tennant not leaving and the specials, a tiny part of my brain did wonder if RTD had basically pulled the greatest conjuring trick ever in convincing us that Tennant wasn't going anywhere then regenerating him. Obviously I'm glad that didn't happen as I doubt he'd have regenerated into Smith... As for cliffhangers, Andozani has a couple, even before the end of episode 4, the Doctor and Peri being shot, and the Doctor basically slamming a spaceship into the ground because he doesn't have time (or space) for a proper landing. "So we play the contest again, Time Lord..." is a good un as well. Doomsday and Utopia are good, but kudos to the Ninth Doctor at the end of Bad Wolf. Dalek "But you no no weapons, no defences, no plan?" Doctor "Yeah and doesn't that just scare you to death."