Totally agree!

One of the most annoying things is when you see a design that is called a "prototype" but it looks like a BADLY done final design.

A prototype needs to CLEARLY be a prototype and that is where balsamiq is awesome. If it does not look like a prototype, then I won't know what elements of the design are bad because of your TASTE in design and which are bad because this is a PROTOTYPE.

In general, EVERYTHING in a prototype should be up for judgement IMO. Don't want people to be judging the colors? Don't put it in the prototype! Don't want people debating how the checkbox should look? Don't spend time delicately designing the perfect checkbox!