One word of caution. I booked a top secret hotel through lastminute a few years ago. Straight after booking I checked the site to see how much they offered the same hotel for as named accommodation - it was £5 a night cheaper than the top secret deal! I contacted them straight away as they have some sort of price match promise thing, but they said it only applied to offers on other websites.
What I would do is, once you've found the top secret hotel you like the look of, work out which it is (not too difficult usually), then have a quick shop around just to check that it is the best deal.
That's 110 words Claire..