Thanks again for the additional help. I wish I would've known about the overnight ferry before I booked my flight from London to Amsterdam!

I considered Ibiza but after doing research, April isn't a good time of year to visit as apparently most of the main clubs and parties aren't happening at this time of the year. It's the top destination for my next Eurotrip in the summer months along with the Greek Islands.

I also added Berlin to my trip based on the recommendations here and my research.

Here is my final city list and how I'm getting between them

NYC > London (6 days)
London > Amsterdam via air (7 days)
Amsterdam > Prague via overnight train (6 days)
Prague > Berlin via train (5 days)
Berlin > Budapest via air (5 days)
Budapest > Madrid via air (5 days)

If anyone has any unique experiences, restaurants, bars and/or clubs in these cities that aren't easily found, please reply!

One of the biggest parties in all of Europe happens in Amsterdamned on Kings' Day (formerly Queen's Day - rock concerts on Museumplein - beer flowing everywhere - fun for folks of all ages but especially younger ones.

https://www.google.com/search?q=king...=1600&bih=1075

Happens every April 30 - not sure you will still be in Europe but if so organize your schedule around this!

Also in Amsterdam at anytime check out the Paradiso for pop music for 20 types and the Melkweg - same concert hall type place but with several other aspects as well - youth centers both run by the city of Amsterdam on a non-profit basis. Legendary places for decades now.

Ofasho, I think flying to Amsterdam is a good choice. I guess the ferry trip is quite long and if you are not a good sailor and the sea is choppy...... not nice:(

The ferry is overnight...you get on board around 9ish I think, you can grab dinner then the ferry leaves at 11...you can stay up it go to bed and they wake you up at 6-7am so you don't notice how long it is. Very fast. Than the train is waiting and you are in Amsterdam by 10am and it saves a hotel. There is a bar and a restaurant and a theatre on board.

The ferry is so big and the crossing is actually smooth a majority of the time except in stormy weather. My dad gets sea sick but found the ferry fine it was so smooth. Obviously if there was horrible weather it could be choppy but from what I have read that is not usually the case.

I second PalenQ's comment on Kingsday. Wife and I completely lucked into a few years back (when it was still Queensday). It is an event like no other, and well worth planning around if possible.

In Amsterdam pick up a free copy of Uit Krank (sp?) a free paper distributed in hotel lobbies, tourist offices, etc that lists all events for younger folks and all ages monthly - parts in English so you can find a place playing your kind of music - jazz, classical, pop, reggae, etc. Sorry I can't remember the exact name but it is all over the place.