For your day trip from Paris you might want to consider Provins. It's a walled town about an hour by train from Paris. We just did it this summer and while we weren't totally 'wowed' by it, it is something different from visiting another large palace and it was interesting enough that I'm glad I went. Here's a link to my trip report and photos - scroll down to day 3 for the part about Provins. http://www.fodors.com/community/euro...swiss-alps.cfm

For a day trip from Amsterdam I think Delft is great. I did several day trips when I was there last year and really enjoyed Delft. Also enjoyed Leiden, and I was actually staying in Haarlem which is the absolute easiest day trip from Amsterdam (15 minutes on a train, and they run constantly. You don't even have to plan it, just show up at the train station and hop on the next train. Delft was actually not much harder. Here's the link to that trip report - scroll about half way down to get to the part about the Netherlands: http://www.fodors.com/community/euro...etherlands.cfm

Here are the photos of Amsterdam and Delft: http://www.pbase.com/annforcier/netherlands

Ive decided to go to Strasbourg for my Paris day trip. I am still undecided for Amsterdam!