and i don't just mean from a learning screenwriting standpoint! i remember there was a summer where i was in a HEAVY book slump. i felt like i couldn't focus and fully get into a fiction novel, so i decided to go back and reread my copy of the before sunrise/sunset screenplays. lo and behold, i smashed through it in a day or so.
there's something so fascinating about seeing which scenes stay exactly the same and which scenes change, either from director input or improv. i love the challengers one for how different certain scenes are for the characters. like the conversationin the car with patrick towards the end. it's such a great way to see how different writers put scenes together and bring characters to life.
also there are tons you can access for free online!