I wish I could post the ones from our corporate repo (massive internal web app for a Fortune 500).
The best in the wild is probably Wikipedia's tests:
https://github.com/wikimedia/qa-browsertests
You really need to abstract with page objects. Even then when your app gets past 30 screens of input your tests get hard to abstract.
I have an experimental way of quickly abstracting common paths without cycles; should probably clean it up and send it as a pull request to Cheezy: https://github.com/cheezy/page-object
