Thanks guys, here are a few. I simplify the titles to read easier, hope you can identify the original. I believe these are some that were uploaded as .zip then I converted to .cbz that did not open in my Nook Color: Young King Cole v2 5, Northwest Mounties 4, Blue Bolt v5 2, Lost Worlds 6, Air Fighters v2 1, Western Adventure 6, White Princess of the Jungle 3, Mary Marvel 7, Airboy 7, Captain Science 4, Prize 68, Ranger Comics 37, Champ Comics 13, Saint 2, Doll Man 32, Guns Against Gangsters 3, Speed 44, Target v9 10.
Hopefully there is a way to have all the great .cbr files readable on a Nook Color. I don't download them as I don't like sitting in front of my laptop to read.
P.S. Is there any way to identify the file type before starting to download? Maybe in the name or comments.