Google Cardboard VR Glasses
Perhaps the simplest VR glasses you can get! They work great and they're a great intro to the world of VR.
Really, for the price they're amazing. They may not last forever, especially if you have kids using these things, but if you take care of them they'll do pretty well for you.
And they work ok. They're not professional grade by any means, but these VR goggles will do the job. They can be a little blurry around the edges, but what do you expect for under $10? If you want better VR goggles, you can expect to pay over $50 more.
So yeah, if you're looking for a cheap way to get into the VR world and test stuff out, this is the way to go!