This cactus looked terrible when I bought it. The second I saw it I knew what it was and how it was supposed to look. It's not as if it was diseased or pest ridden, just clearly sun deprived , dehydrated, and knocked around a bit from shipping and employees not trained to take care of cacti.
|See? Looks not so nice.|
The cactus above is probably Gymnocalycium friedrichii (or mihanovichii var. friedrichii depending on which taxonomy you agree with, I haven't figured out which is "official") Below is how it looks with full sun and regular water.
|ID hopefully in a few days|
This cactus is supposed to be a purple or red color, it isn't sunburned.
This one below, is sort of a "before" picture. I didn't take one when I first got it of how sad it looked too, but you can see it's light deprived. It's most likely just a too green Gymnocalycium mihanovichii.
|Not quite as bad, but too green for my taste|
Here it is again below with proper light and water.
|ID to come shortly!|
When these bloom, I'll be able to verify the ID's that were made. They are definitely Gymnocalyciums, those are easy to spot. If you can't tell by looking at the body of the cactus, the flower buds will give it away. Buds are always spineless, wool-less, bristle-less, smooth and scaled looking. I guessed on the species ID's and my guesses were verified on a forum, so we'll see if any of us are any good at ID'ing cacti, or if I labeled them prematurely.
EDIT 7/9/12 *Links to ID updates below*:
Cactus #1 ID
Cactus #2 ID