When I was last year in Holland, I've bought the Museum Pass for one year for about 400 museums (35 Euros). Although my visit lasted for 3 weeks only, this card was a great! deal. Another recommendation is to buy the train pass, which will save you 40% of the train ticket if you go after a.m. That card is valid for one year and 3-4 people can use it simultaneously. For buses I recommend Strippencard for 18 strips.

In Ireland they also have Museum pass and passes for buses, buses and trains, Republic only or all Ireland. That's worth if you go for a long distances.

There is a good transport and Museum pass also in Dresden.

When you come to Madrid, than buy metro pass for 10 trips (5.5 Euros instead of 1.1 for one trip).

Sincerely, Alex Elbert Jerusalem Israel.