Casino Royale (Bond explosiveness)
Eragon (dragon riding)
Night at the Museum (CG chaos)
Pirates of the Caribbean: Dead Man's Chest (Davy Jones!)
Poseidon (ship sinking worked before)
Superman Returns (flying! lifting things!)
X-Men: The Last Stand (
Which begs the question: What of the trippiest f/x experiences of the year. In 2006 no effects work freaked me out more than that sequence at the feast in Pan's Labyrinth and none moved me more than those in The Fountain, which I suppose fall into the non-Oscary trap of actually working as storytelling (see also: the snubbing of the f/x in Eternal Sunshine of the Spotless Mind) rather than primarily as surface level of "wow, how'd they do that?" razzle dazzleables.
My tech predictions here.
And this is worth checking out: Boing Boing points us to a really interesting web site on the special effects in the Pirates sequel, which are obviously heading for the win.