Opuntia humifisa, probably both of them. The stem shapes can change according to cultural conditions.

Man, I wish I could find one that's cold- hardy to here (it was a year with low snowpack and low temps after the snowpack left) Somehow, the piece that I had got deaded.

It certainly helps that my garden is on top of a sandpit (all my cacti are growing on 2" sand mulch on top of 3" soil on top of 30+' of sand) and also on a decent slope. If you need a couple new pads to try again just let me know.