jib71

Depends on where you're going. Monorail offers a nice, seamless connection to Yamanote line and is handy if you're heading toward Tokyo station, whereas Keikyu is handy for points west. (Please take the trouble to type "Keikyu." It took me a couple of minutes to work that one out).

LapLap

The other advantage with the monorail, particularly when returning to Haneda Airport, is that it is much harder to make a mistake and board and inappropriate train than it is on the Keikyu line.

Personally, I use the Keikyu line for this journey, but that’s only because Shinagawa is a more convenient station for me. On the Keikyu line it can get extremely crowded when going Southbound towards Haneda. I suspect the monorail (perhaps the fact that it costs a little more) may not be quite so crushed. The view from the monorail (which hugs the waterfront) must be better too.

kaka

oh yea. talking about which i remember there was an in-station shortcut from JR to monorail which i took at around 5am. This would be a handy one connecting to tokyo/ueno.
However sometimes the JR-monorail connection ends up being a 160m walk... or maybe that was the subway-monorail connection?

jib71

JR to monorail connection is well signposted and easy to follow.
For a seamless monorail to JR connection, sit toward the rear of the monorail and take the exit at that end of the platform at Hamamatsucho. From there, you have a couple of escalators and a very short walk to the JR station.

love_to_travel

For all 4 of these priorities I would unreservedly recommend the Richmond Hotel Premier Tokyo Oshiage.

1. You can get there from HND without transferring trains on the Keikyu Main/Airport Line (which becomes Toei Subway Asakusa Line at Sengakuji, no need to get off).
2. You can get to NRT from there without transferring trains on Access-Tokkyu (many stops but no need to get off).
3. The Tokyo Skytree is right across the street from the hotel. Which in addition to being a great way to see the entire city also has a huge mall and gazillions of restaurants
4. Oshiage station (which is where the train from HND will stop and where you will board the train to NRT, see #1 and #2 ) is right across the street from the hotel

also,

a. There are elevators from the platform to the station proper and from the station up to street level, so no need to worry about taking luggage on stairs/escalators
b. There is a supermarket right under the hotel
c. Asakusa is one stop away, so you can visit Sensoji
d. While the rooms in the hotel are small, it is still very comfortable

I visit Tokyo about six times on average per year and I always stay at the Richmond Hotel Premier Tokyo Oshiage, no matter where in Tokyo my business takes me.