Butch Cassidy and the Sundance Kid (1969)

I hate the 5.1 of this one. Many added Foley effects that have no business being part of the mix. The 5.1 adds many unnecessary nature effects, like the constant presence of insect noises (even in a couple indoor scenes, where the window is clearly shut!), water splashy effects, etc. All hoof sounds have also been replaced with modernised recordings, and the explosions have been changed as well. The mono is available only on the US blu-ray.