I really really really want to go to the Mutter Museum in Philadelphia. I love medical stuff to the point that some people would find it a bit creepy.

Someone has already mentioned The City Museum in St. Louis, and I have to say it is one of my favorite places ever. Even if you don't have children, it's worth checking out. It really is indescribable. The "creator" of this amazing place passed away last year, which was a huge loss for the whole city. He's created some other cool things around the area, but nothing compares to the City Museum.

The art and history museums in St. Louis are quite nice too, and are both free (as is our zoo, and all three are located in the same park!).

A few suggestions, at least for those who might tend toward the nerdy pursuits:

1) Kraków, PL - Museum Podziemia Rynku
A museum dedicated to the history of the main square of Kraków, excavated under the main square. Nice mix of exhibits, excavations, and multimedia.

2) Fredrichshafen, DE - Zeppelin Museum
I loved this one, because I'm a gigantic nerd. But it was fascinating to see the history of the zeppelin.

3) Midleton, IE - Jameson Distillery
Interesting if you love whisky, and a great excuse to drink in the morning: The tours are less busy and at the end eight people from each group get a whisky tasting (the rest just get one).

I'd really love to make it there sometime - also to see the boneyard.

On a related note, the Evergreen Aviation & Space Museum (mentioned earlier ITT) in McMinnville, OR also has an awesome missile launch simulation.

HMS Victory, the oldest commissioned ship in the Royal Navy, at Portsmouth, UK.

This was Admiral Lord Nelson's flagship at the Battle of Trafalgar in October 1805.

The Packard Museum in Dayton, Ohio:

It's set up in an old Packard dealership restored to early 20th century design. It has a lot of old Packards and details about them and some excellent docents who will tell you great stories about the cars. Definitely one of the more fun off the beaten path places I've been

Classic Car Collection in Kearney, Nebraska. It is on the NE side of the Cabela's store on the east end of town.

Downtown "on the bricks" we have MONA (Museum of Nebraska Art).

Joslyn Art Museum in Omaha.

Loveland Museum and Gallery in my hometown of Loveland, CO.

The National Air and Space Museum in D.C. was pretty cool when I was there many years ago. Pretty much any of the Smithsonian museums are worth going to as well.

Lilliesleaf farm in rivonia south Africa outside of Johannesburg. It was a farm where Nelson Mandela and other anti apartheid activists lived and planned resistance activities. Eventually they were captured and put on trial in the infamous treaon trails. It has been turned into a museum with some great interactive exhibits and interviews with All sides including the Afrikaner police.

Ho chi minh city. Musurm of the American war period. Gives you a totally different perspective of what happened.

Easter island. Really just one big outdoor archaeological museum.

And closer to home any and all presidential libraries. Been to JFK Reagan Nixon ford Clinton. Want to see all It doesn't matter your politics it provides a lens of America during the years Of each presidency.

My fiance and I really enjoyed the Amsterdam Museum when we were there in January — it has tons of interesting information and interactive exhibits that are way beyond the norm for a history museum.

I'm also fond of the Whaling Museum in New Bedford, MA; one of the employees randomly gave us a personal tour and shared all kinds of trivia that we never could have gotten by ourselves.