Do they have double tails? I can't quite tell from the photos D:
Anyway, if yes, they're fantails, and if no, they're commons But considering the body shape, they sure look like fantails!

Lovely fish! Especially fond of the calico in the last photograph. The fish in the first photograph is definately a comet; identified by the long, flowing single tail fin and the "submarine" shaped body. The second fish may or may not be a gold fantail, though I am inclined to think it is one. If it has a paired tail fin than you know it is not a comet. The body shape of a fantail goldfish is usually more rounded in the belly than that of a comet, as this one appears to be. The third goldfish in the last photograph is a common calico goldfish. The tail of the common goldfish is more rounded and shorter than that of a comet.

Altogether, you have a lovely assortment of finned friends. 

I,d say the first on is a common goldfish and the last two are fantails.

Looks like everyone agrees! Haha,  I think we've all been there wondering about a fish!