"old-fashioned" turn-based all the way for me.
It's by far and away my favourite system, because it doesn't rely on me to be quick enough (or press space/pause every few seconds).
Dragon Age: Journeys showed how this is done relatively well, but I find it useful in a variety of genres. Notable games being X-Com, Fallout, Jagged Alliance, Civilization, some of the Ultima games, Heroes of Might and Magic, King's Bounty...
Need I say any more?
Of course everyone has their preferences, and I wouldn't want to force my preference on anyone, but I would like to see a little bit of a return to a classic turn-based approach.