There is a relatively new Novotel at AKL, it's not "in" the airport but it's on airport property and only about 100 yards from the exit of International arrivals, connected by a walkway or just walk across the passenger pickup zone. Really nice rooms, better than the average Novotel, great staff, but the hotel restaurant is a let-down as the food is decent-not-great, very pricey, and the service is really bad. Comfy beds, nice furnishings. Internet access is (like many hotels in New Zealand) quite pricey so if you don't get it free by way of status, book an executive room-- cheaper than regular room + pay for your wi-fi.

Another vote for the YVR Fairmont!

Hyatt in MCO is another one of my favorites. The rooms are remarkably well-soundproofed; one of the quietest on-airport-property hotels I've visited!

Slightly off-topic, the Renaissance in St Pancras International Rail Station in London is an excellent location, and a very posh hotel. It's very pricey even by London standards and I don't reckon I will stay there again unless they're having a big sale, but you really can't beat the location. Hilton in Paddington Station was starting to look a little worse for wear last time I visited so hopefully they will be sprucing up a bit (or may hvae done so already), great location where the Heathrow Express drops you off!