Make no mistake about it: Crossroads for the draw is one of my favorite cards. And Stables is a card which has some restrictions, but within them is very powerful. They combine like Peanut Butter and Jelly. Or bananas. Or chocolate. Or whatever you want - the point is, they're good.
The concept here is simple: Stables cycles away treasures. That eventually gets you a higher concentration of green cards in your deck, which lets Crossroads draw more. The green never goes away, which means each crossroads draws more, and more, and more. Conversely, when you have lots of green cards, your Stables run the risk of getting stranded, and Crossroads can bail you out.
This is generally most at home when there isn't great trashing and/or other ways to draw cards. Add a little bit of sifting in, and it's a surprisingly powerful, resilient drawing engine, on top of which you can add whatever payload you want.
In which I crush a Minion deck
In which I defeat a(n admittedly not totally committed) Rebuild player