Thunderbolt and Lightfoot might not be a great movie, but it's sure a good one. It was written and directed by Michael Cimino, who went on to bigger (although not necessarily greater) things. Eastwood is a bank robber known as The Thunderbolt because he uses an anti-tank cannon to break into a vault. Bridges (Oscar nominated) is Lightfoot. He drives fast. There's also a great supporting cast, including George Kennedy, as brutal as he ever was, Geoffrey Lewis, and Gary Busey.
The plot is a little complicated, but here goes. Eastwood is hiding out from members of his old gang because they believe he betrayed them. He didn't, but he's the only one who knows where the money from their last job is hidden. They catch up with him, and he's saved by Bridges (purely by accident).
The two team up, with Bridges just about stealing the movie with his performance as a happy-go-lucky guy, and they bond. They get together with Kennedy and Lewis and go to find the money, which was hidden in an old school. They find the school is gone, replaced by a big new one, so Bridges proposes that they pull another job, robbing the same place they group had robbed before.
They pull off the job (Bridges in drag!), but of course things go wrong and then wronger. The movie, which had started off in a lighthearted way and which had been quite funny most of the time, has taken a much darker turn. The ending is bleak.
If you've never seen this one, give it a look. Highly recommended.