Jenbel has pretty much hit the nail on the head. If you are looking at one programme I would go for Priority Club for the following reasons:
- Far better coverage in the UK
- Good selection of hotel Worldwide for redemption
- Points breaks deals 5000 points per night at selected hotels including Intercontinental (normally 40,000 points per night)
- You will rack up an amazing amount of points especially if you follow the advice on the master promo thread on the Priority Club and Intercontinental Hotels board on this site
Oh and welcome to the UK and enjoy London