I like Sacrifice of Angels too, but I disagree about the disappearing fleet. I definitely think it's a very egregious deus ex machina, though I agree it's an important part in the Sisko/Prophets story. However, I really don't think damaging the Dominion War story like this is worth advancing that storyline, and I'm sure there would've been some way to do it without deus ex machinaing the Dominion War storyline.
That said, I really love the scene were Sisko pleads with the Prophets to help. And the Dominion evacuating the station, especially Weyoun's "Time to start packing" and Dukat's fury is great too.