How is the Great Gatsby title ironic?

I confess, I never did read this book, and all that I know of it is from watching the newest movie with DiCaprio, lol. But, here's my take on it from watching the movie:

Gatsby seems truly great in many ways: his ability as a businessman to get rich shows he's great in skill and knowledge, and the fact that his driving force is love shows that he's a loving man. But when you rethink it all, he got rich illegally (though, some people think every rich person breaks laws to succeed :) and while it is for love, he's a pawn in infidelity. He's blinded by love, and he's doing so many bad things in order to try and get this girl that he loves. Yes, the people attending his parties think he's great, but they're really only there for the party and the booze...he really doesn't have any true friends except Nick, Daisy and Tom (though, like the rest, Daisy just seems into him as long as he's giving her fun times)

I think in the beginning Nick respects Gatsby, and that the respect increases as he learns the truth about Gatsby's love for Daisy. How impressive for someone to go to such lengths to prove his love for a girl! But I think near the end, I think Nick's respect drops drastically as he begins to realize Daisy's loyalty is truly to Tom, and she just seems to be using Gatsby for fun. The fact that Gatsby either doesn't realize it, or doesn't care and lets her get away with it; blinded so much by love that it ends up getting him killed...you can't really respect someone for that.

Again, no quotes (sorry), but perhaps this will at least give you something to work off of.