Nothing is more unappealing to me than an overdone interface. If the site is worth going to, the content should shine and the layout should be clean and easy to navigate with the "important" (for lack of a better word) content right up front. Marketing and your subjecct matter has a lot to do with it as well. If you're running a niche site (like I am), you need to deliver the goods at a short glance to keep people coming in.

.2c