retardaholic 

A person who is addicted to repeating stupid acts on an ongoing basis. No matter what the outcome is they still continue to do it. Similar to an alcoholic.

That guy is a retardaholic, he keeps touching the electric fence.

retardaholic by raiderbill September 1, 2009

Returnaholics 

Customers who buy items only to take them home and use them for a short period of time and then return them realizing they didn't need them at first but they just wanted to see what it's like to have it.

In 2010, $185 billion worth of merchandize is bought and returned to the store by returnaholics.

Returnaholics by NoahS1 May 11, 2010