Many people would use a train from Haneda Airport as transportation. There are 2 lines. Tokyo Monorail and Keikyu line.
Which is better?
It depends where you go!
Tokyo Monorail is useful for going to Tokyo Big Site and Odaiba (Change to Rinkai Line at Tennouzu Isle station) and transferring to Toei Oedo Line ( get off the final stop Hamamatsucho station and go to Daimon station by foot). Moreover, they offer the weekend and holiday ticket Monorail and Yamanote Line Discount Ticket, so, Tokyo Monorail might be better for going to Yamanote line station than Keikyu line.
(Please note. Keikyu Line also stops at a Yamanote line station, Shinagawa. So, I cannot say Tokyo Monorail is always better than Keikyu Line for going to a Yamanote Line station.)
Keihin Kyuko Line (Keikyu Line)
Keikyu Line is useful for going to Yokohama, Shinagawa, Asakusa, Oshiage and more. Especially, Shinagawa station is a stop station of Tokaido Shinkansen. So, if you will transfer to Tokaido Shinkansen, Keikyu Line is very convenient.
Keikyu Line are running widely. It brings you many places. It is convenient, while it would bring you wrong place if you take a train for wrong direction!! Especially, trains going to different directions are stops at the same plat home in Haneda Airport. In addition, Keikyu Line has one local line plus 4 express lines. So, some express trains may pass through your destination!! Please make sure where the train stops before you get on.
(It contains trifle dogmatism and prejudice)
|Tokyo Monorail||Keihin Kyuko Line|
|Convenient stop for transferring||Tennozu Isle, Hamamatsucho, etc.||
Shinagwa, Keikyu Kawasaki, Yokohama, etc.
|Advantage||Nice view! (I think. It partly runs along Metropolitan Expressway in parallel)
(I think) Monorail is quite rare, so, it is (maybe) fun.
Convinent for going to Bigsite/ Odaiba ( Change the train at Tennozu Isle)
|The running area is wide!
It stops at many convenient stations.
|Disadvantage||Stations are a few.||Taking a wrong train, you would go to wrong direction.
The multiple types of express trains make you difficult to know where the train stop.
*1 In Japanese, they offer the other discount tickets too, however, somehow, the english official site doesn’t have the information. So, I follows the official site.
Click here for Tokyo Monorail Information
Access to Haneda Airport Tokyo Monorail (English)
Click here for Keihin Kyuko Line Information
Haneda Airport Access Guide (English)