This is a Polish port, but there is not much to see in Gdansk. Should take a bus tour as we did, otherwise you will miss all of what you can see there, which is not much. we were shown Lech Walesa's home on the outside.
Riga is very pretty, although not as prepared for tourists as Tallin. However, some in our group liked it even more than Tallin, so it is a question of preference. Would have liked to see it more in depth.