*cough cough* Ornamental is right. A clown pleco is a Panaque (so is Flash Gordon in the picture, he's a mature 5 year old, and about 5 inches long.) They're reclusive moody fish, but Plecos are the whole reason I keep fish so with the right tank setup and care they can be viewed and enjoyed. It just normally requires zucchini and a moonlight kit. As to which of them are better? If by better you mean, better at digging large dusty holes, and uprooting plants, and having an all around obstinate personality, as well as being better to look at...then the clown/panaque is totally the way to go. If by better, you mean better at cleaning the glass endlessly and keeping your tank shiny, then the nerite snail is a much better option, but thats a topic for another thread. My BN does continually eat algae off the glass etc, he just produces so much poop in the process its pretty much an even trade-off, I'd have to say that both my plecos are ornamental fish, and if i didn't get them specifically because i love keeping them I'd have regretted their purchase long ago.
P.S. Panaques eat wood primarily as well as fresh veggies, zucchini is this guy's favorite, and while he's apt to rearrange the whole tank in a tiff, he never eats on my plants, but he is kept well stocked on various types of food and even a wood buffet. I'm sure if i slipped up on his diet for even a week there'd be lots of dead plants around.