Need help identifying these plants, please
edited June 2019
I'm pretty sure the top one is a house leek
Second one looks like an aloe. Last is a variety of crinita cacti.
The first one looks like an Echeveria and the second is like my Haworthia, which is probably H. attenuata.
Lots of good pics on g****e if you just put in the name.
Not able to help much on cacti though. If you are lucky it may flower, which would give you another clue