Let's break it down:
Light - when they enter Mordor(?) (the caves where they meet the balrog)
Light - on his sword, when he fights the balrog
Flare - when he comes back from the dead and dazzles Aragorn(?) (the ranger)
Flare - when he chases away the... undead wyverns(?) in the battle in the third movie
When Sauron(?) drops snow on the party, Gandalf becomes delusional and thinks he's a wizard and can counterspell.
As the movies came out one by one I was like "Gandalf will start casting real spells this time." Alas, that never came. Even in the most epic battle in the third movie he rides out on a horse and chops at orcs with his sword. What the fuck! At least telekinesis some orcs like you did with Sauron! Oh wait, he totally owned you, never mind.
that would be the mines of Moria and Saruman.
And hey, as usually, a movie is a poor indication, in the books he doesn't even do the force battle with Saruman in the tower, at least it's never said HOW he battles him.
He can also cast Aura of Fear, anyway, or rather, aura of awe, because it don't work too well on enemies. It's also funny that he can actually do far more, but it's never specified. Like in the fight with the Balrog he SHOULD need some serious mojo up his sleep, but WHAT it is Tolkien keeps for himself.
That being said, Wizards are still unbalanced. Like Gandalf never wears armour, but doesn't get more than scratches nonetheless. So I guess he can also cast Mage Armour or is just a really good melee fighter in addition
. Gandalf the gish, anyone?