American Hustle is a really fun film - perhaps too fun, in that what makes it fun is that it's like watching Goodfellas again. And, that's the downside, it's trying way too hard to actually be Goodfellas.
But, other than that it's a good film and a good ride. Christian Bale and Amy Adams are perfect. Bradley Cooper isn't quite as good, but it's unfair to put almost any actor in a room with Bale and Adams and have them not seem like the weaker actor.
What makes this film worth watching is just watching Bale's character try to keep on top of everything. He spent most of his life running short cons involving at most one or two other people - where he could control every step of the operation. Now he suddenly has to run a long con involving dozens of support people and he can't master every string. Beyond that, instead of ripping off small business owners in Long Island, he's tasked to rip off members of Congress and the Mob. That would put anyone on edge.
The running theme of the film is that everything is a con - we con ourselves, we con others and we get conned - and that whoever can run the best con at a given moment will win.
Finally, if they ever had an Academy Award for Best Uncredited Cameo this film wold win it in a heartbeat.