I went on Nemesis and Air more than ten times each (helped by working out how to stay on, rather than go around the 10-20 min queue again). I still think Nemesis is better than Air - especially in a hailstorm :) - but partly because I wasn't expecting much, I found Air much more enjoyable than my first go on it in the summer. It's particularly good at sunset.
In contrast, Oblivion was a disappointment. The first time is really scary, this time, my second, wasn't.
New to me were the haunted house ride (fun, and I think it's being replaced this winter), river ride (better than the one at Thorpe Park, but not as good as Parc Asterix or Eftling), motorized coaster (better than at Chessington and Thorpe) and 3D cinema showing something from the 60s (fun, but faded).
Hmm, how to arrange more out-of-school-holiday trips there?