#1 looks a lot like a Hedgehog cactus. Usually they're not quite that upright but I think it is one. There are pediocacti, echinocereus and one other I forgot. About 70 I think. Cactiguide.com might help. Most of them have big needles but the shape seems similar.

This post was edited by CooperDR on Fri, Dec 5, 14 at 21:42

I'll take a guess at a few of them. With my old eyes, some of the pics are a little small for me. (seriously, still recovering from herpes on the cornea)

3 possible Gasteria - what did the flowers look like?
4 Aloe juvenna
5, 7 Aloe hybrids - I find these difficult to ID as many look similar
6 x Alworthia 'Black Gem' or Aloe 'Walmsley Bronze'
10 Aloe nobilis
13 Rhipsalis pilocarpa - does the plant have needles?
15,16,17 Sanseveria
19 Crassula ovata

Hopefully some smarter folks will chime in for you!

#1 is Cephalocereus senilis (Old Man Cactus). I have one of those. I am curious about #11 as I also have one and don't know what he is.

I think 3 is a Gastworthia; 4 is Aloe Pepe (an Aloe haworthioides hybrid); 5 could also be Aloe Doran Black; 6 is indeed an Aloe/Gasteria hybrid called Black Gem; 7 is one of many possible Kelly Griffin aloe hybrids; 8 is Acanthocereus tetragonus; 11 is a Mammillaria; 12 is Echeveria pulvinata or some close relative; 14 is missing; 15 could be a young Sansevieria Moonglow; 16 and 17 are Sansevieria trifasciatas; 18 is also missing; 20 is Mammillaria rhodantha var. pringlei; 21 looks like Aloe Crosby's Prolific

Thank you all! This has been really helpful!

#3 is Aloe hybrid "Twilight Zone"

Fireballsocial - I think #11 is Mammillaria hahniana. Maybe mine has a double head? the opposite swirl is a little unusual I think.

#2 possibly be Euphorbia virosa ?
frank

#8 is a castle cactus