Scientifically known as botia macracanthus, the clown loach is could very well be the most popular loach availible (khuli loach is also very popular). clown loaches do not have scales, so be careful with fish medications.
The behavior of the clown loach is very nice because they are very social. Clown loaches will rest on their sides. Though it looks like they are dying, they are just resting.