Finally got around to watching the 70's Malick films. Man, does that guy know how to shoot a scene to capture the beauty of the location. Badlands i'd recommend to anyone and has clearly inspired True Romance and Natural Born Killers. Days of Heaven is amazing but is a movie that will be hit or miss for a lot of people.
As for the 30 for 30's, i've seen them all I think except the most recent The U part 2. My Favorite I think is the Best that Never Was that focused on Marcus Dupree, but pretty much all of them are extremely well done.
And Shark Tits, I don't think you have to be a Masshole to find Whitey Bulger interesting. As part of the basis for the Departed (along with adapting Infernal Affairs) and his crazy corruption/political connections he's definitely of interest to many people who like gangster/crime documentaries.