To dye or not to dye, that is the question

So I'm bored with my hair again (what else is new?) and therefore contemplating dying it dark. A coworker of mine recently dyed hers really dark (almost black) and it looks fantastic on her.

I used to get highlights a couple of years ago. I started out really cautiously (red highlights only) because I was nervous about having them look horrid. I see so many girls with fake looking highlights and I didn't want to become one of them.

After I adjusted to subtle highlights, I added more...and more...and more...until my hair looked like a mess. As a result, I dyed it really dark (which is also my natural hair color) and kept doing so until all the highlights grew out. I'm now contemplating getting highlights again...but maybe in red? Red is such a hard color to maintain though; it washes out really quickly. Right now my hair is a dark brown color.

Any thoughts?
I thought it would be fun to take a vote to see what readers think so I created a poll (top left corner).

Here's a pic of me sporting highlights and another one of me with dark hair.