How about 'Cutlass', written and directed by Kate Hudson, starring Dakota Fanning, Kristen Stewart, and Kurt Russell?
Great because it is a short where most of the elements of the film are impeccably professional: locations, props, performance, music, editing, cinematography... but the story and directing kinda... well, suck. A glaring example of how surrounding yourself with talent isn't everything. If you're wondering what's missing in the movie, I think it mainly comes down to the story and how it's told and what the actors do to tell this (aka directing), which doesn't seem purposeful, in my opinion. It really highlights the importance of a director on set.
Then again, this is the only video on YouTube with like no negative comments, so maybe I'm full of shit and Kate Hudson is the next Orson Welles.