In the code I help maintain in my day job, I see a lot of the following code:

try
{
/* code */
}
catch(Exception)
{
}

I see it in several different languages almost daily. It really frustrates me that my colleagues and predecessors did this. I stamp it out ruthlessly.

Here is a great post on why empty catch blocks are bad. Here is a great question and series of answers on StackOverflow about best practices for exception handling.