I give a name check to this blog about every six months or so - mainly because, apart from this place, it's my first port-of-call on a daily basis - and it's good.
Every year they do a month long series - 30 days of Screenplays.
The good thing is they give you download sites for screenplays you might not have thought were out there - and a bit of analysis.
If you work in long format - or fancy having a go - you can't beat reading the real thing.
Here's the link:
http://gointothestory.blcklst.com/tag/30-days-of-screenplays
Enjoy.