There is a common misconception among some web site developers that they (and therefore their clients) must choose between form and function. They are under the impression that there is a battle of Form vs Function. I'll admit it; I'm guilty of using this sort of language from time to time, but in my conversations there is a harmonious resolution. Recently I've had clients want to parse the difference in cost between a site that is functional and one that is cumbersome. I've even heard of developers who tell their clients they don't need a good looking site so long as it works. This, I say, is rubbish!
You should not ever have to chose between form vs function. You should have Form + Function.
Once all of us kids were moving out of the house my parents decided to vacate the humble dwelling of my childhood and up-size. Despite the clear insult, this was pretty exciting for all of us. As I'm sure all of us know, houses are (out of necessity) built on a sturdy foundations. That pretty much covers the extent of my house building knowledge. I know that the foundation must be good. The house must stand. The product must work!
The other thing I know about building houses is this: When they are finished NO ONE shows off their foundation. No one talks about how sturdy the frame is or how well it will stand up against a storm. Those things are all important. Those things provide worth, but they don't add value.
Value is added by the aesthetics. Value is added by how nice it looks from the street. Value is added by the finish on the doorknobs and the texture of the cabinets, by the vaulted ceilings, the open floor plan and the hot tub in the bathroom. There is a temptation to call these things luxuries (and some of them are), but honestly they are lifestyle indicators. The form is what morphs a house into a home. The beauty is what distinguishes a place to stay from a place to truly live. The amenities take something that is doable and makes it something desirable.
There is no reason that you shouldn't have both From + Function. It should be noted that an attractive form to you does not have to be attractive to me or anyone else outside of your target audience. While we're at it, what is functional for me might not be very functional for you. Both the form and function should be designed and developed with each client in mind, but one should never be sacrificed on the altar of the other.