Open the largest m2ts file which is located in BDMV\STREAM folder.
This works for most Blu Ray discs I've come across, but not for one. I've ripped all of my BD movies to ISO using SlySoft's AnyDVD HD software, and the disc
Inception has many *.m2ts files in BDMV/STREAM, none of which are feature length (the film seems to be distributed across all/most of the files in this directory).
It'd be nice if VLC could play .mpls playlist files, so films like this can be played in their entirety. Note I'm using VLC on Linux, and it can read most Blu Ray I've come across (but no menus yet).
EDIT: I read elsewhere on this forum that the BDMV folder can be opened directly by VLC, and it plays the feature properly (thus far, still watching/testing). After further watching, it plays everything in the directory, including film documentary ("making of...") stuff I don't want to see when I'm watching the movie.