If you live in the Netherlands it's definitely worth investing in the Museumkaart if you enjoy museums and expect to go several times in the year. The museum card isn't cheap either (€49.50 for adults and €22.50 for children), but once you've bought it, you can freely enter as many museums over the year as you want. After just three visits to major museums in the year you're then reaping the value of the card.
There's no information on the Museumkaart website in English. You can buy the card online, but will have to pay €4.95 admin costs. Alternatively - and cheaper - you can buy your card at any of the museums where it is valid, and use it to enter freely straight away.
The card will get you in to the top museums in Holland, including the Van Gogh Museum, the Rijksmuseum and the Stedelijkmuseum in Amsterdam. Closer to home, here are a few examples of the museums you can visit for free with the Museum Card in the Helmond and Eindhoven area:
Gemeentemuseum Helmond - which includes two locations: the Boscotondohal which has a permanent art gallery on ground floor and temporary exhibitions on top floor, and Helmond Castle (Kasteel Helmond)
Van Abbemuseum, Eindhoven - which features regularly changing contemporary art exhibitions, in addition to a permanent collection of modern art, including key works by Lissitzky, Picasso, Kokoschka, Chagall, Beuys, McCarthy, Daniel and Körmeling.
Museum de Wieger, Deurne - former home of the doctor and expressionist artist Hendrik Wiegersma. The museum usually shows temporary exhibitions, but also holds his wonderful collection of local folk art (which he accepted as payment from patients with little money), as well as his paintings, which you can arrange to see if you contact the museum in advance.
Museum 't Oude Slot, Veldhoven - a old farmhouse displaying objects of the local culture, and the People's Print Room. Also linked to an exhibition space on the city hall (Gemenntehuis) showing comtemporary art.
Search the Museumkaart website for more ideas.