The source with explanations[http://www.gilt.com/giltmanual/category/essentials/?page=1]

Also, no self-respecting guy ever uses "ass" as a modifier

• A Seven-fold Tie
• A Go-to Karaoke Song
• At Least One Jacket with a Gratuitously Colorful Lining
• Luxurious Underclothes
• A Go-to Whiskey
• A 10'' Chef's Knife
• A Tailor Who Knows You By Name
• Working Knowledge of Knots
• A Serious Pair of Wingtips
• A Cast Iron Skillet
• A Wallet That's Worth More Than The Money In It
• Socks That Show You Are Not Afraid
• An Espresso Machine
• The cell number of at least one Malte D (Mickey Bakst)
• A Jacket with Elbow Patches
• One Good Quote in a Dead Language
• Proper Hangers
• Alternative Evening-wear
• A Pair of Heirloom Cufflinks
• Nice, Nice Sheets
• A Watch to Pass on to Your Son
• Broken-in Denim You Bought Raw
• A Classic Cardigan
• Knowledge of How to Pilot a High-performance Car Around a Track
• A Three-piece Suit
• Harry Smith's Anthology of American Folk Music
• A Denim Working Shirt
• A Dirty Little Secret
• A Good Old Fashioned (and Totally Modern) Felt Fedora
• A Velvet Blazer
• A Proper Writing Implement
• Wine Glasses That Cost as Much as a Bottle of Wine Each
• White Jeans
• A Week's Worth of White Dress Shirts
• A Go-to Joke
• A Rugged (Yet Versatile) Pair of Work Boots
• Chinos. That Actually Fit
• The Harrington Jacket
• A Fine Gauge Sweater
• Brown Suede Shoes
• "The Bag, Man"
• An Umbrella nice enough not to forget
• A Plaid Shirt
• A gratuitously nice notebook (Red Moleskine)
• The Perfect White Shirt
• The Penny Loafer
• Go-to-Hell Pants
• A classic Panama hat
• the pink shirt
• a classic pair of aviators
• a polished pair of dress boots
• a well-made pocket knife
• a navy blazer
• a weather-defying waxed jacket
• a piece of original art
• a proper pair of shoe trees
• a rugby shirt
• a barber you don't have to talk to
• a tweed sport coat
• a great pair of leather gloves
• a serious winter scarf
• a suitably slim dress belt
• a cable knit sweater
• a stable of seasonably appropriate ties
• a tuxedo
• the pea coat
• a hip flask