I believe the first one (2 pix) is Notocactus mammulosus (synonym, Parodia mammullosa, not sure of spelling & not sure which name is being used now). Seems silly to say, Stephanie, but I think the other is a Mammillaria (there are gazillions). Maybe someone else will recognize it & pipe up!!

is ther different varieties of this cactus? I searched for this cactus and it is a positive, thank you very much I have many cacti and will be posting more of ones i'm not sure of their names.

I see the resemblance now. You wouldn't happen to have any clues at to what that great big tall one is, would you? It's my only cactus that remains unnamed. It looks like a really big cutting off of an even bigger old cactus. It looks similar to Trichocereus peruvianus, but those cuttings are very expensive, and I only paid $15. Perhaps, though, the place I bought it from was unaware of what it was. Either way, I think it's definitely a Trichocereus.

I agree with Haworthia, possibly H. attenuata. I can't tell what the flowers look like. This is the flower from my plant.