I've had luck at Once Upon a Child (found a dream beauty there and it's one of the only places I find G1s other than the goodwill outlet) and I like how it's organized. At mine they put all of the toys in baggies grouped by type (like a set of barbies in a package, etc.), so it's really easy to dig through. Also, since it's a child's consignment, there are naturally more toys than other consignment stores. It's worth a look!
But this year I haven't had super huge luck for ponies in my area...the garage/tag sales for the most part were TERRIBLE this year. Oh well, better luck next time!