What sort of thing do you enjoy? Singing in the rain and top hat have had great reviews but are quite traditional. If you want something more modern - Shrek is brilliant and I've heard good things about Billy Elliot too.
Oh yes to Wicked. Can't beat Les Mis for power...not an easy evening out though! Even though they are seemingly for kids, don't write off things like Lion King and Matilda. Both very credible for any audience. Then you have the more traditional stuff like Top Hat and I think Singing in the Rain will still be on then. Book of Mormon is going to be huge but I think you're too early for that and prob too early for Charlie and the Choc Factory which is another biggie next year. Billy Elliot is good too.