You can access more than 1,200 airport lounges with the Amex Platinum - here are the best ones

American Express has a deep-running partnership with Delta Airlines, and one perk is that Platinum cardholders get access to Delta's Sky Club lounges whenever flying with the airline. With more than 30 locations, Sky Club lounges offer snacks, complimentary soft and alcoholic drinks, fast Wi-Fi, and spacious, comfortable seats so that you can relax before your flight. Some of the larger locations feature showers, too.

Depending on the airport, these lounges can vary in size by a lot — for example, the Tampa, Florida Sky Club is a lot smaller than the flagship locations in Delta's Atlanta hub — though they're generally all comfortable.

My personal favorite Sky Club is in Terminal 4 of New York's JFK airport. Not only is it spacious without feeling cavernous, but it also features a great food and drink selection, clean and well-stocked shower suites, and work areas where you can set up and be productive.

The best feature, though, is the "Sky Deck," a large outdoor porch with loungers and tables where you can enjoy a drink (or use the Wi-Fi) in the fresh air while watching planes take off and land. There's something so relaxing about being able to go outside, even when you're post-security in the terminal. The Sky Club in Atlanta at Concourse F also features an outdoor Sky Deck (pictured above).

Access is complimentary for cardholders when flying with Delta, and guest passes are available for a discount.

Delta Sky Clubs and the Centurion Lounge tend to be more useful when flying within the US (although both have expanded internationally), but you can still access lounges all around the world through Priority Pass, a network of more than 1,200 participating lounges (and a few spots like restaurants and spas) at airports around the world. The network includes some airline's lounges (like the Korean Air business class lounge at JFK), as well as spaces operated by third-party companies and airports.

Amex Platinum cardholders can enjoy an included Priority Pass Select membership, which grants access to you and up to two guests at a time (as long as there's room — Priority Pass lounges can get crowded). If you have an international version of the card, instead of the US version, be sure to double check the guest policy for your card's Priority Pass benefit.

Amenities vary by lounge, but typically feature free snacks, drinks, newspapers and magazines, showers, and more, all separate from the hustle and bustle of the main terminal. Recently, Priority Pass has even started adding airport restaurants and spas to the network. At these restaurants — including the Grain Store at London's Gatwick airport — you'll get a certain amount credited on the bill for you and each guest. At the Grain Store, for example, each guest is entitled to a £15 credit.

While it's hard to pick out the best from a pool of over 1,200, a few that stand out among frequent flyers are the Air China Lounge in Beijing, the Aspire Lounge at Zurich, and the Plaza Premium Lounges in Hong Kong and London Heathrow. I'm also partial to the No. 1 Lounge at London Gatwick, which you can fly out of on Norwegian Air Shuttle for great prices.

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