The best choice of pet duck has to be a call duck. They're miniature breed (grow to just bigger than a pigeon), so don't grow too large. You should have a pair, not a single duck, to give them company and otherwise they will be very loud indeed- they mate for life and create lots of noise if seperated.

All ducks are pretty free with their mess, and it comes with them unfortunately.

Call ducks are amusing pets, and will follow you around and can be handled also. They need a small area, about 5ft sq for the pair, and a small house about the size of a kennel. They'll give you eggs too.

An alternative good pet could be an Indian Runner duck, but they're a lot bigger.