In the hospitality arms race (yes, "pillow menus" and a "soap concierge" actually exist), luxury hotels are luring guests—particularly men—with decadent in-room spa treatments that go well beyond the pedestrian massage. "Our business travelers routinely book after hours for lack of time during the day," says Ryan Crabbe, senior director of spa operations and development for Hilton Worldwide. "It's about meeting guest expectations on their schedule and in a convenient space." Here, some of the best excuses to stay in your room.

The Hotel: El Encanto, Santa Barbara, California
The Treatment: The en suite Oxygen Facial ($245) smooths wrinkles and enhances elasticity.
What To Expect: A spa technician wheels a massage table and an oxygen machine into your bungalow, then selects the appropriate professional-grade Intraceuticals serum, applied with pressurized oxygen to penetrate deep—think nonsurgical lift.

The Hotel: Aria Resort & Casino, Las Vegas
The Treatment: Guests in the three-bedroom Sky Villas can request the Royal Shave ($180).
What To Expect: In the villa-suite's "barber room," outfitted with a shampoo bowl and salon chair, a master barber cleanses and exfoliates your face before applying a hot towel to open pores. After an aloe-vera lather, you'll get a straight-razor shave, first with the grain, then against.

The Hotel: The Sebastian, Vail, Colorado
The Treatment: After a day spent in ski boots, thaw out with the Crazy Mountain Pale Ale Pedicure ($100).
What To Expect: The yeast and carbonation in your pedicure beer bath soften and soothe tired feet, which are then exfoliated with a bamboo scrub. Next comes a lotion massage, and your nails are clipped and buffed while you sip a pint of locally brewed beer.

The Hotel: The James Royal Palm, Miami
The Treatment: Detoxify after a long night out with the Organic Sea Plant Soak ($85).
What To Expect: After a full-body exfoliation and massage, a spa therapist draws a hot bath infused with organic sea salts, vitamin-rich kelp, and aromatherapy oils, then applies a chamomile mask as you steep.

The Hotel: The Capella, Washington DC
The Treatment: A consultation and Gent's Cut in your own well-appointed bathroom ($110).
What To Expect: A stylist from the recently opened Luigi Parasmo Salon considers your face shape, hair texture, and grooming regimen before even pulling out the shears, then shows you how to recreate the style with Oribe products.

The Hotel: The Delano Hotel, Miami
The Treatment: Get your nutrients the same way Rihanna does—call for a Vitamin IV Treatment ($200).
What To Expect: A technician from the hotel's Club Essentia will assess your needs and select a cocktail of vitamins, minerals, and antioxidants you can take intravenously to correct for any imbalances.

The Hotel: The Sunset Marquis, Los Angeles
The Treatment: If you haven't had time to hit the beach, opt for a quick Customized Spray Tan ($200).
What To Expect: A la carte airbrush tanning applied inside a pop-up tent brought to your room (to minimize any residue). The unscented, organic L.A. Bronze solution goes on with a light tint and takes just 15 minutes. Within four hours the color will deepen to a healthy tan.

At the newly renovated New York Palace, guests staying in the $25,000-a-night Champagne Suite can enjoy treatments like the Arnica Muscle Melt on the private rooftop, complete with a spa Jacuzzi, a fireplace, and views of St. Patrick's Cathedral.