for the window that pops up when you first start a torrent, and you select what files to download, I think a tree view thing (listing the folders in the torrent, and the files within each of those folders) be easier to choose what you want. as you could easily deselect one entire folder in a single click.
the best example I can think of to be a little more visual with what I’m thinking, is something like the Winamp installer. I know others have used the same type of setup, but they’ve all slipped my mind.