A great snack that is also good for you is popcorn. As long as it's simply popcorn. Not coated with butter, or sugary flavor, or cheese. Just plain old popped corn.
Air-popped popcorn has the fewest calories. You can eat a lot of it and get filled up – enjoying the crunchiness at the same time. It counts as a grain serving in my "Joy of Weight Loss Eating Plan."
Microwave popcorn isn't bad, but look for the lower-fat varieties without artificial flavors or colors, which taste just as good as the higher-fat varieties to me.
Have very little (or none) of the sugar-candy coated variety, or the cheese flavored. They may call it "smart" but not if you’re trying to lose weight!
Don't be fooled by movie theater popcorn, either. It's often very old and stale--often popped somewhere else and stored in giant plastic bags. And if you add the "butter flavor," you're getting some artificial scary stuff with who knows what kind of nasty oil, and preservatives. It's also sincerely high-calorie. It can be as much as 1,000 calories and a ton of fat in a big bucket.