Indeed, Dutch stamps are very excentric. I have many of their stamps and until the 50s/60s, they were 'conservative', meaning they were similar to other countries. Engravings with portraits. But even then, their annual Children stamps were always colorful.
But since the 50s, their stamps have become more and more strange and interesting, and they do surely make you think.
For example, I can't stop loving this "Beautiful Netherlands" series that started in 2005:

Below is an annual Anniversary issue:

In 2010 they celebrated:
- VVV - Dutch tourist office (typical images of Netherlands, like windmills and typical buildings)
- Tropen - An institute responsible for the study of cultural and sustainable development (thus the forests and wilderness)
- Duinrell - An amusement park celebrating it's 75th anniversary
- The Euromast in Rotterdam - sort of like the towers in Niagara Falls or a much smaller CN Tower (stamp has the Euromast and a Rotterdam landscape)
- Djoser - means "alternative travel", and is a type of travel agency that organizes different kinds of excursions (thus the array of Egyptian landmarks and camels)
Definitely a different way of seeing stamps. Too bad TNT is in a mess.