Money at rail link, train to the city, switch at Asoke to the boat into the old city, walk to hotel, shower, food, rest.
If I come by train: Hop on the boat or into the subway to the old city, same as above. Later talk a walk around the area towards the river, relax at the river, some food and thinking life is good.
I prefer the old areas over the CBD or Sukumvit.