Though naturally I grow mainly carnivores, there are a few other plants that share the greenhouse and other various place in my home as well. These guys do live in the greenhouse next to some Drosera and Nepenthes seedlings, though only until I have a place to put them permanently.
Carnegiea gigantea, or the Giant Saguaro
Various barrel cacti
And, my one surviving Stenocereus thuberi, or Organ Pipe cactus
dragon fruit and Peruvian pear also do well in my greenhouse, the dragon makes sense, but I was shocked by the Peruvian's. But the Peruvian are only happy whilst small, once they have germinated ad reached about 15-16cm (4-5months in) they start to rot if not removed, dragon fruit on the other hand are more than happy.
Which type?, I have the red, small yellow (which I think may be the wild(est) version), the white and another larger yellow one, so far all fruited but the large yellow. Also their flowers (like most cacti) open at midnight and are huge, 25-30cm is no exaggeration.
Just make sure you let them grow on a trellis or fence as they do not fruit until they cant grow any higher, and then they fruit at the top regions, this is an issue I have had people ask me about as they plant them on tree's in excess of 50ft and then cant get to the fruit.
They are very fast growing for a cacti and from seed to 1m takes less than a year if they are grown well.
Hylocereus undatus, the common white fruited red one. Seeds came from a fruit at the store. Not sure if I have a place to trellis such plants, but I've also read that if they exceed a 10 lb. minimum weight they'll begin to flower as well. Seems to be supported by pictures I find.
The red form is the most compact of my dragon's, and 2-3 plants are happy on a 3M long by 2M high trellis, as they reach out I just cut them off and feed them to the cows (who love them, especially just before they flower)