I had seen bits and pieces of It's A Wonderful Life on TV over the years, but until a few years ago I never saw it all the way through.

However, three or four Christmases ago a local theatre was playing it, and I was fortunate enough to have my first full viewing of It's A Wonderful Life in a theatre in December.

It was one of the best movie-going experiences I've ever had, and by the end I was torn between crying and jumping up and down cheering.

It's hard to know why George Bailey is such a great character, but I think a lot of it has to do with how the audience knows of his ambitions, and yet he makes such a huge sacrifice that is entirely selfless (but has huge ramifications on his town). It also doesn't hurt that James Stewart plays him so perfectly.

I'd say the scene following the death of his father, where he defends the Building & Loan against the protestations of Potter & the Board, is probably one of the most heroic moments I've ever seen in cinema.

@Joey: I concur. It's an incredible scene, one of several in the movie. And featuring my favorite actor of all time James Stewart.

[...] he’s experiencing a bit of the George Bailey syndrome going on: he gave up what he’s known to chase a dream, only did not find it. And now has been driven [...]