There are many different brands of popcorn avaiable, and the truth is, most of it pops up pretty similarly. But there are a few things you should look for, no matter what brand you're buying.

1. Choose a package with an expiration date far in the future. The older the popcorn is, the more it dries out. The less moisture there is inside the popcorn, the smaller the kernels will be. If there is very little moisture, it won't pop very well at all.
2. Don't automatically go for the name brand. Off-brand popcorn often pops better than the name brand popcorn, especially if the expiration date on the off brand popcorn is much further in the future than the name brand expiration date.
3. Try to smell the popcorn kernels through the bag, if possible. If you smell anything unusual, like a musty, stale odor, then purchase another brand.

Of the brands I've tried, there were a few that I've been satisfied with every single time.

1. Great Value (Wal-Mart's off brand)
2. Winn Dixie's store brand
3. Bi-lo's store brand

I've also had pretty good success with Orville Redenbacher's, but NOT in their microwave brands. I've found that Orville Redenbacher's microwave popcorns are very inconsistent and often very stale.

Although brands may vary, I've found that there are differences between the types of popcorn, as well.

Yellow popcorn tends to pop large, fluffy kernels, and is relatively consistent, while white popcorn pops smaller kernels that are often tough. I have had some white popcorn that was very good, but as a whole, I prefer yellow popcorn.

Colored popcorn is fun, but it's often inconsistent. Since most people don't buy the colored kind, it can sit on shelved for many months before being purchased. So unless you see a very good expiration date on a bag or jar of colored kernels, it's best to avoid it.