A L O E
For the last year or so, I've worried about this guy the least, which might have been a bad idea. It requires more water than your average succulent, but not too much, and it doesn't need a ton of sunlight. This one grows out of the center, so I'm constantly going in and checking on new growth. I'm a little worried about it at the moment though, because a couple bits are drying out at the ends, and one guy has fallen down a little. I'm currently trying to nurse this one and see what's going on.
C A C T U S
This guy is the easiest going of the three. It needs more sunlight than the aloe, but it rarely needs to be watered. From past experiences, I've learned that you have to be really careful of how often you water them, because even if every other week seems off, it'll become all water and cave in, and no one wants that.
M E D A L L I O N
This is the first non-succulent plants I've ever owned, and I'm obsessed with it. The leaves have a really cool pattern on the tops, and the bottoms are purple. Throughout the day, the leaves separate and then bunch together again. It needs more sunlight than all three, so I've got it sitting at the edge of my work space, closest to the only window. It does need more water than I thought, but that hasn't been too much of a problem. I almost killed it once by not watering it for a week, but all is well now. I'd really recommend this kind of plant for anyone who wants to start collecting but doesn't know much.
*Note: I am definitely not an expert, just a crazy plant lady, and your own plants could react differently. Don't take these tips as law. Listen to your plants.