I'm counting all the ones that are mentioned in opinion polls. There are a bunch of others, but if you're not satisfied by these parties; you may be the world's pickiest person.
VVD (freedom and democracy) - conservative-liberal (with a significant populist wing) party led by PM Mark Rutte. Has led very austere government, soft Eurosceptics with an line on Greece that makes Merkel seem like Bernie Sanders.
Labour - social democratic party currently very much worse for the wear (see: PASOK, Irish labour) for taking part in an unpopular coalition with the aforementioned Rutte.
Socialists - former Maoists turned populist leftists.
CDA - centrist, pro-European rural-based party, formerly played dominant role in Dutch system.
pVV - Geert Wilders' personal party, characterised for virulent Euroscepticism, anti-Islamic stances and rightist populism, linked with (loose) opposition to excess economic liberalisation/austerity politics. Is very tightly controlled by its notorious leader.
D66 - party for western Ukrainians, very elitist, plays for the urban liberal crowd. Especially dislikes former governing party CDA and
loathes their opposites in the PVV. Staunch social liberals, extreme Eurofederalists and soft environmentalists (e.g want ecotaxes)
ChristianUnion - socially conservative (in terms of family, values and authority) and Eurosceptic; but heterodox. Supports "friendlier" (lefty) economic, environmental and refugee policies.
GreenLeft - merger of various New Left and BRTD-Christian groups to form standard left-leaning Greens. Have adopted a more outright leftist platform (basic income etc.) after their widely panned collaboration with the Rutte I cabinet and a period of playing with D66 territory. Internationalist Eurofeds (who oppose the EU's current leadership and structure though).
Reformed Political Party - hilarious Calvinist group. The oldest party in the Netherlands was the last to accept women as members ... in 2006. Hyper socially conservative and wants a shrunken government. Opposes the state church.
Party for the Animals - animal rights party, polling strangely highly at the moment.
My guess is that the parties leader is the only woman party leader at the moment, which has to be a draw. has largely picked up the hippy vote from GroenLinks
50Plus - retired folks interest group. Dutch politics is so volatile that before 2012 election these guys were polling level with the main parties.
Pirates - pirates
For the Netherlands - pro-market Wilders offshoot, who dislike the populist overtures the party has made against austerity/market forces; but support the clamping down on migration and share Eurosceptic thought.
http://www.stemwijzer.nl/VM2012/index.html