Shitty deus-ex-machina character. Goes away, comes back just in the right time to save the day. Goes away again. Aaaaaand comes back to save the day just in the nick of time.

Spoilers...

From the beginning of FOTR, you get the sense the character is mischievous and looked at with distrust from the general hobbit population. But he is also loved by the children and Frodo. He shapes the journey of Frodo by convincing Bilbo to leave behind the ring. Gandalf, being one of middle-earths protectors, tells Frodo to hide the ring while he goes to find info on it. He returns from his journey to the archives and confirms the identity of the ring as The One Ring. Realizing the danger the Shire is in, and Frodo, he sets Sam and Frodo on a journey to get them out and meet him later. He is going to seek advice of the lead wizard Saruman. Upon arrival, Gandalf discovers that Saruman has turned bad in fear of a returned ancient evil, and Gandalf is taken prisoner. This standoff and escape show that Gandalf is both pure good, and wise in his knowledge to escape. After escaping, Gandalf meets Frodo in Rivendell and a meeting between leaders of the races of middle earth takes place, with Gandalf basically the moderator. The decision is reached to destroy the ring, and when Frodo volunteers to be the ring bearer, Gandalf agrees to guide and protect him on the journey, along with several others. For the first part of this journey, Gandalf watches over Frodo, warns him of dangers, and gives him advice and wise counsel. It's not dissimilar to the relationship between Dumbledore and Harry Potter. You get impression of a true connection between these characters. When their journey turns to the mines of Moria, the group is chased by an ancient demon that is too powerful for them to fight. Gandalf turns to fight and tells the others to go on. When Gandalf falls protecting the rest, you feel real loss (if you haven't read the book).

That is just the first leg of his journey.

This character is AWESOME.

He's the best wizard character in film history.

I just think they should have gone more into his temptation with the ring, since that is his only real character flaw and it's only glimpsed when he is offered the ring by Frodo at the beginning of Fellowship.