I have to agree with the Arched or Skunk variety.
I have three that are very active and very hardy. They went into the tank after I thought it was done cycling, but turns out it wasn't, and they are constantly searching for morsels.
I think mine have ESP with the other cory's in the tank, because they all seem to stop and start scavenging at the same time, even though they are in different parts of the tank. Also, last night, I saw all three of them resting on leaves, on different plants in different parts of the tank.