Amsterdam to Milan

24 hours in each place means that you'll have limited time to look around. Could you help us on the right track by saying what kind of trip you are looking for, what your interests are etc.? Why did you select the places you mention, for example?
And what do you mean by "euro ticket"?

Ok, The idea of this trip came around as we are going to Barcelona for a friends stag weekend and i suggested to a couple of friends that we should fly to Amsterdam and make our way through europe, finishing in Barcelona for the stag do. Looking into possible travel options, we came across a 'global interrail pass' that apparently allows us to travel on five days over a ten day period. Would this be valid from Amsterdam to Milan?

Unfortunately, due to other commitments, we cannot travel for as long as we'd like which is why we have so little time in each place. The plan at the moment is to spend 2 nights in Amsterdam, then one night in Brussels, Munich, Innsbruck and Zurich, finishing with 2 nights in Milan, where we fly to Barcelona. This then gives us the opportunity to stay an extra night somewhere and sacrifice a night in Milan. These places were selected, very simply, by looking at a map and choosing a fairly straight route from Amsterdam to Milan, whilst visiting as many countries as possible. If anyone can recommend swapping any places, then please, we'd love to hear your suggestions.

As we have limited time in each city, we'd like to have a rough idea of what we want to visit so that we don't waste time while we're there. Although we're not really into museums, we would like to see landmarks and take in the local cultures during the day and then experience the night life in the evenings.

Thanks in advance for your help.

Most straight route would be Amsterdam - Cologne - Munich - Innsbruck - Milan.
Brussels between Amsterdam and Cologne is a detour but possible.
Zürich between Munich and Innsbruck is a really big detour.

Your itinerary is too much big city concentrated in my view.
What about skipping Brussels and stick to the more direct route through the Middle Rhine Valley?
Between Munich and Innsbruck I would recommend the route via Mittenwald and the Karwendel railroad.

IMO Brussels doesn't warrant a detour, better spend that time in Germany. Milan is also not that special apart from the Duomo. Abalada's itinerary is a good one.

[Quote]These places were selected, very simply, by looking at a map and choosing a fairly straight route from Amsterdam to Milan, whilst visiting as many countries as possible[END Quote].
Is visiting as many countries as possible a key target?
Better tell what special interest you have. E.g. architecture, scenery, nightlife.
As for scenery and culture:
I cycled from Amsterdam to Bergamo (close to Milano) in September (ok, not compatible) and what's nice: post nr. 3 (abalada) gives a great suggstion, the Middle Rhine Valley, the nicest part of the track. Just get off for some hours in Oberwesel, walk up to the castle, have a fantastic panorama on the Rhine, or St. Goar. And Mainz is in my opinion the nicest town I visited, because it's not TOO big, so you leave it with a feeling really to have been there.
Then in Cologne you only spend some hours to visit the Dom, built against the Hauptbahnhof (main railw station). On te other hand when you prefer nightlife I assume the Kneipen in Cologne are more favourite than Mainz' equivalents. No expert!;-)

the Dom, built against the Hauptbahnhof (main railw station)
I think it'd rather be the other way around ;-)

Thanks aribo, I have been wrongly informed then;-)
By the way, recently I read that we thank some UK pilots who decided - when arriving there with their load - not to bomb the Dom, Cologne being a main target in WW II for the Allies.