My soft spot is always Phantom, so the candles in the lake always does it for me.
I love mufassa's ghost in Lion King.
I still can't understand how they did the reversing ageing thing in Dracula.
Was not impressed with Chitty, since from the seat i had in london i could clearly see the boom that the car is attached to.
Les Mis always makes me cry when Javert climbs the barricade and it spins around and suddenly all the dead people are gone and he is left alone.
I totally loved the finale of the Little Shop of Horrors revival when the plant extends out into the audience.
Norma's mansion decending from the flies.
Not so much of an effect, but i almost peed myself in Mamma Mia when the boys flap onstage in those flippers.
Only thing i thought cool in wicked (as far as effects go) are the 2 portraits in the Shiz scene how they go all psychadelic when Elphaba freaks out about Nessa.
and lastly, I loved the ending of xanadu with all those disco balls (what can i say, i am a sucker for disco balls)
http://www.flickr.com/photos/27199361@N08/ Phantom at the Royal Empire Theatre