unfortunately, we only had one day for hakone and man, am i sorry! we used the 1-day pass and we loved it. the highlight of the day was the azalea garden of that hotel. amazing, especially because we were lucky enough to be there during azalea peak season.
but the best deal i heard of is the 3-day pass. for 5500 yen you get free access to train from shinjuku to hakone and then to any means of transport within the national park - trains, bus, ropeway, boat cruises, etc. they have lots of museums (little prince, venetian glass, open air art museum, etc) and onsens (the most amazing being the wine onsen).
go and enjoy a wonderful time in nature, in the close neighbourhood at mount fuji! :)