Most "airport hotel" sites are booking engines, and most of those list everything within a few miles of the airport. The latter is fine for some things, but there's a qualitative difference between a bed you can walk to (or take the airport people mover to) and one which is a taxi or shuttle ride away.
São Paulo-Guarulhos International (GRU): Fast Sleep (English)
(landside: within Terminal 2, Ground floor, Wing C)
(airside: in the connector between Terminals 1 and 2, along the VIP room corridor)
Manila Ninoy Aquino International (MNL): Manila Airport Hotel (across from Terminal 1)
Manila Marriott Hotel (in the Newport City complex across from Terminal 3)
Maxims Tower at Resorts World Manila casino (in the Newport City complex across from Terminal 3)
Chengdu Shuangliu International (CTU): Some hotels are within a few hundred meters walk of the terminal building, across the parking lot to the right towards the Cheng Shuang Highway (成双公路) airport exit.
In order of proximity: Chengdu Airport Hotel (成都机场宾馆), CAAC Ju Long Hotel (民航巨龙酒店), Chuangang Hotel (川港宾馆), Civil Aviation Hotel (民航宾馆), and the Cheng Yun Hotel (成运酒店), none with their own official websites. Plenty of links from Chinese hotel booking sites; just search for the characters.
(Examples: Chengdu Airport Hotel at kuxun.cn, Chuangang Hotel at scslw.cn, CAAC Ju Long Hotel at sc666.com, Civil Aviation Hotel at eflye.com, review of the Cheng Yun Hotel on daodao.com. Make sure you are looking at the named hotel in Chengdu and not some other place, as names of hotels are often repeated in other cities.)
Taiwan Taoyuan International (TPE): There's a Novotel on the airport grounds on the other side of the aviation museum, but it's not within walking distance. Nothing else landside is closer. If you're still airside, see the Evergreen Transit Hotel in Terminal 2.
Washington Dulles International (IAD): Washington Dulles Airport Marriott (something of a hike across the parking lot on the other side of the Daily Garage)
Zurich Airport (ZRH): Radisson Blu Hotel, Zurich Airport (across the street on the left side of Terminalparkhaus 1 as you exit Terminal 1)
Airside, the Dayrooms and Rest Area can be found in Transfer Area D.
Moscow Domodedovo International (DME): Domodedovo Airhotel (about 500 meters from the terminal building across a long parking lot along the airport access road--avoid walking this in winter)
New York LaGuardia (LGA): No hotels on airport property but there are five across the Grand Central Parkway on Ditmars Blvd. over the 102nd St. overpass facing the US Airways Terminal (C): the LaGuardia Airport Hotel, the New York LaGuardia Airport Marriott, the Courtyard New York LaGuardia Airport, the Hampton Inn New York - LaGuardia Airport, and the LaGuardia Plaza Hotel.
There's also the Clarion Hotel La Guardia Airport across the 94th St. overpass, nearer the airport's Central Terminal.
Antalya (AYT): There's an IC Hotel on the airport grounds but it's over a kilometer from the nearest terminal (International Terminal 1).
Baltimore/Washington International Thurgood Marshall (BWI): There's a Four Points by Sheraton at the airport but it's next to the daily garage parking structure, a long walk from the terminal building.
Copenhagen (CPH): Hilton Copenhagen Airport (directly connected by covered walkway from Terminal 3)
Palma de Mallorca (PME):
Salt Lake City International (SLC):
Kunming Wujiaba International (KMG): Aviation Sightseeing Hotel Kunming (昆明机场观光酒店) (directly across the parking lot from the terminal building)
Airport Hotel Kunming (昆明机场宾馆) (just a block behind the Aviation Sightseeing Hotel)
No official hotel websites, but there are reviews of both the Aviation Sightseeing Hotel and the Airport Hotel Kunming on daodao.com, as well listings on the usual Chinese hotel booking sites.
Fort Lauderdale – Hollywood International Airport (FLL):
London Stansted (STN): Radisson Blu Hotel London Stansted Airport (directly connected by covered walkway to terminal two minutes walk away)
I've stayed here. Expensive but very comfortable, with excellent service and a great bed. Fully up to the standards of the Radission Blu (SAS) chain.
Dublin (DUB): Clarion Hotel Dublin Airport and Radisson Blu Hotel, Dublin Airport (both a not too pedestrian-friendly walk across the road and off to the right as you exit Terminal 2, with the Clarion one street closer than the Radisson Blu)
Manchester (MAN): Radisson Blu Hotel Manchester Airport (located across from and between Terminals 1 and 2, and connected by covered Skylink moving walkway, slightly longer walk from Terminal 3)
Bewley's Hotel Manchester Airport (5 minutes walk via pedestrian walkway from Terminals 1 and 3; 15 minutes walk from Terminal 2)
Crowne Plaza Hotel Manchester Airport (past a carpark and across a parking lot from Terminal 3)
Milan Malpensa (MXP): Sheraton Milan Malpensa Airport Hotel & Conference Centre (connected to Terminal 1 with the adjoining Malpensa Express rail station)
Honolulu International Airport (HNL): OHANA Honolulu Airport (the closest hotel to the airport, about 500 meters past the Overseas Terminal Parking Garage as the crow flies, but not that direct on foot)
There used to be a 17 room Mini-Hotel landside in the Overseas Terminal itself, but it closed in 2002.
Most of these hotels have shuttle buses which run more or less often, and in some of the less pedestrian-friendly locations you will definitely want to take advantage of them.
Caveat emptor: Some of the hotels listed may not be up to first world standards, but they happen to be within walking distance of a terminal. Read reviews and do your homework.
Airports listed are those which have had at least 20 million passengers in one of the calendar years between 2007 and 2010.