If you're looking for something special for someone special and have a substantial budget, you can't go wrong with a Michael Kors watch. The craze kicked off a couple of years ago for 'boyfriend sized' gold and rose gold watches and Michael Kors does these best.
I picked up the Parker MK5616 model when I was in New York last Spring and despite how fickle I am, my love for it is still going strong. I think the MK5616 is one of the more wearable styles and won't date as easily as some of the larger funkier models. I picked mine up in Bloomingdales for $250 less the 10% discount for being a foreigner, woo! You can get it here at House of Fraser for £229. The complete indifference of retailers to the currency exchange rate mechanism is lamentable, but if you don't know anyone going Stateside soon you will just have to bite the bullet on good old GB prices!
One word of warning about Michael Kors watches - they are in fact made by Fossil. While I love my Fossil watches, I find it very cheeky that you're paying such a mark up just to flash the MK badge for what is just Fossil quality. I do think that the rhinestones have dulled a little since, but at least none have fallen out. Remember to be careful not to spray perfumes or other aerosols near it as it may discolour the metal.
All in all, it was $250 dollars well spent - who wouldn't love to open a rose gold beauty on Christmas morning?!