As far as I'm concerned, Birdemic is the better of the two because... it's so bad. It's so appallingly bad. The thing about The Room is that it's terrible, but not quite enough to be hilarious apart from in a couple of places (notably Wiseau and his unbelievable accent/ acting), which makes it... just plain bad. Birdemic, however, throws everything about the entire process of filmmaking out of the window, making it hilarious.