I consider them to be a wardrobe essential, mainly due to their versatility. They can be dressed up or down and are extremely easy to colour match. They make a great alternative to jeans as well and will give your wardrobe more depth.
Here's a few applications of the chino, apologies for the terrible picture quality. Note that the colour isn't quite the standard khaki, but the point gets across nonetheless:
You could wear this to go to the shops on the weekend.
Change to a shirt, and you can go to a bar.
Throw on a blazer and you're in a club.
Take the time and shop around and remember the two golden factors: fabric and fit. Make sure the fabric is comfortable and of a good quality and make sure that they fit your leg shape. Don't just buy something because of the brand.
If you're feeling a bit uninspired with the myriad of blue and black jeans out there, step out of your comfort zone and get a pair of chinos. You just might like them.