Well I can beat you lot because I'm 55! And like a previous poster, a teacher, so there is no excuse, I should know better, but I love it. Started watching it with daughters a few years ago. I love seeing how the other half lives, love seeing the food, the parties and the clothes.
Find the characters, with the exception of Proudlock and Rosie, rather dim - their collective educations cost more money than I'll ever see - and this both fascinates and concerns me. They also often prove the old adage that you can't buy class.
The really early series were low budget, with awkward pauses and less 'created for your entertainment' stuff, and I actually preferred those. My favourite laugh out loud bits are when they 'accidentally' bump into each other, and act all surprised.
A few series ago, when Binky broke up with Mytton there was footage of her in her bed, supposedly just awake, fully made up and perfectly done hair, waiting for him to call...brilliant.
It's like a really posh version of Acorn Antiques...