This poker room is big enough to comfortably play there but still, I wasn't able to find the exact restricted countries in their terms of service.
In german, but I think you are able to understand/speak it:
https://www.pokerstars.eu/de/poker/promotions/terms/prohibited-jurisdictions/Is PokerStars the only poker room for people with dutch IP? (question to the hall community).
Americas Cardroom is not restricted for dutch people according to this:
14. SPECIFIC GEOGRAPHIC RESTRICTION: Residents of Sweden, Guadeloupe, French Guyana, Mayotte, Réunion, Martinique, France, Spain, Italy, Turkey, Louisiana, Kentucky, Maryland, New Jersey, Delaware, Nevada or Washington State are not permitted to view this site or use any of the games accessed through software downloads provided hereby. From time to time, in its sole discretion, ACR may amend the list of specific geographic restrictions from which You may not access any of the Services.
Source: https://www.americascardroom.eu/poker-customer-support/terms-and-conditions/
In general it's quite hard to find good poker sites nowadays besides PokerStars, since Poker isn't booming anymore. The smaller sites all lack traffic, FullTilt was bought by PokerStars, others were closed by FBI etc. According to
this, IDN Poker is quite big, but I don't know that site and The Netherlands seems to be restricted anyway. GGPoker might be an option for you, since dutch customers can play there.