A college degree is an investment that will last a lifetime and one of the most reliable ways to increase your lifetime earnings. The Bureau of Labor Statistics reports that Americans with a bachelor's degree have median weekly earnings of $1,173, compared to just $712 a week for those who have a high school diploma.

And some colleges are noted for providing an above average return on investment. Edward Fiske, former education editor of The New York Times and creator and author of The Fiske Guide to Colleges says defining what makes a school a good deal is no easy task.

“What college costs for one person is going to be different for another person,” Fiske tells CNBC Make It. “It depends on who you are.”

Factors such as financial need, financial aid, merit scholarships and ability to graduate on time can dramatically impact how much attending a school will cost a given student. For instance, a private college with an expensive sticker price is not always more expensive than a local public program. Students should work with schools directly in order to asses how much a given school will cost them and can ask for the "discount rate" in order to determine how much the average student actually pays to attend.

“But that said,” continues Fiske, “there are reasons that some colleges tend to be better buys than others. What we’ve done is looked for great schools that for one way or another have tried systematically to keep their costs down.”

For instance, Birmingham-Southern College (BSC) announced in 2017 that the school would be reducing tuition and fees by more than 50 percent starting in the fall of 2018.

"The marketplace spoke, and we listened," BSC President Linda Flaherty-Goldsmith tells AL.com. "Students and families are telling colleges all across the United States — and they're telling us — that encountering a high published price is a real barrier to a high-quality education."

Every year, the Fiske Guide to Colleges releases a ranking of the 10 "best-buy" public and the 10 "best-buy" private colleges.

Here are the 20 schools that came out on top for 2019: