Gallerist Larry Gagosian on Parisian museums, crew cuts and a JK Rowling novel

My personal style signifier is a pair of Levi’s 501 jeans and one of the 500 or so T-shirts that I collect from wherever I go. I’m a casual guy and rarely wear a tie, so this is my uniform of choice. I also keep my hair in a crew cut for ease. I think it suits me. From £70; levi.com

The last thing I bought and loved was a Wilson Pro Staff tennis racket. I’m not great at tennis, but I love it and play four or five times a week during the summer. I’m hoping this racket will improve my game. From £170; wilson.com

And the thing I’m eyeing next is a special-edition Leica M9 Titanium camera by Walter de Silva. He is a car designer and his Audi design team has reinterpreted this classic camera in titanium and given it a leather trim. It is a beautiful – and compact – collaboration, perfect for my travels. £19,800; leica-camera.com

A recent “find” is Sushi Sasabune in Los Angeles. It serves A-plus omakase sushi and, while it is literally a hole in the wall, the food is just unbelievable. LA does unassuming sushi bars in shopping malls very well, but this one is above and beyond. 11917 Wilshire Boulevard, West Los Angeles (+1310-478 3596)

The last music I downloaded was John Coltrane’s My Favorite Things. I am a huge fan of jazz from the 1960s and John Coltrane and Miles Davis are hard to beat. This particular album features jazz versions of pop favourites. I also recently added two classics to my collection: Bob Dylan’s Tempest and Free Jazz: A Collective Improvisation by the great alto saxophonist Ornette Coleman.

In my fridge you’ll always find non-fat Greek yoghurt and fresh pomegranate seeds. This fruit is part of my Armenian heritage and I eat the seeds on my yoghurt every morning. You’ll also find a bottle of champagne – most likely Dom Pérignon – as well as eggs, cheese and all the staples. I have a very well-stocked fridge.

The last item I added to my wardrobe was a pair of green lizard Gucci loafers. I got them in Beverly Hills and I’m trying to figure out when I’m going to wear them. I’m not sure there’s an occasion for this particular pair of shoes. From £1,130; 347 North Rodeo Drive, Beverly Hills, CA 90210 (+1310-278 3451; gucci.com)

The one artist whose work I would collect if I could is Henri Rousseau. His paintings are extremely seductive and strange – his work stands apart from the rest of art history. His jungle paintings in particular are just amazing. The Beyeler Foundation has one of my favourites and the Museum of Modern Art has some great ones, too – but his work is incredibly rare and virtually impossible to get hold of. fondationbeyeler.ch. moma.org

The best gift I’ve given recently was a beautiful vintage Rolex watch to my girlfriend. This rose-gold GMT model is very rare and I bought it at auction at Christie’s. It is an oversize watch that is substantial yet elegant at the same time. christies.com. rolex.com

And the best one I’ve received recently was a drawing that the American painter John Currin gave me for my birthday. It’s a small picture of a woman in the colours of Picasso’s Rose Period and it hangs in my bedroom in Amagansett, Long Island. gagosian.com/artists/john-currin

The people I rely on for personal grooming and wellbeing are Enzo and Ken, the barbers at The Dorchester. I travel so frequently that I am reliant on haircutters away from New York to keep my crew cut in shape. Park Lane, London W1 (020-7499 0759; thedorchester.com)

The site that inspires me is the ocean near my home in Amagansett. I love the coastline at any time of the day or night, but I particularly like to swim in the sea in the afternoon. Away from the pace of the city, this peaceful landscape just charges me up.

My favourite websites are few and far between. I like Artsy because it makes more than 50,000 pieces of art, from institutions from the Guggenheim to the British Museum, accessible to people all over the world. I’m also an Amazon fan – I’m a book junkie and when I find a title that intrigues me I want it straight away; this provides almost instant gratification. amazon.com.artsy.net

My style icon is Gianni Agnelli. He was a dear friend and everything about the way he lived his life was incredible, from his impeccable dress sense – which often included beautiful suits paired with ties worn slightly askew or even a pair of hiking boots – and his Mediterranean yachting adventures aboard the Knut Reimer-designed Agneta to his business acumen. I aspire to his lifestyle but fall miserably short.

An unforgettable place I’ve travelled to in the past year is Athens. I was so glad to see this beautiful city come through a tumultuous time and look vibrant again. I stayed just outside the centre at the magnificent Arion Resort & Spa, where my room was just 10 feet from the sea. 40 Apollonos, Astir Palace Resort, 16671 Vouliagmeni, Athens (+3021-0890 2000)

And the best souvenir I’ve brought home is a book from the Beyeler Foundation in Basel. Ernst Beyeler: A Passion for Art is a series of interviews by Christopher Mory that really illustrate this collector’s devotion to art. It was a gift from my friend [director of the Beyeler Foundation] Sam Keller, which makes it even more special. Baselstrasse 101, CH-4125 Riehen, Basel (+4161-645 9700; fondationbeyeler.ch)

An indulgence I would never forego is the expensive haircut I get about once a fortnight at John Frieda, across the street from my New York gallery. I could save money by walking a few blocks to a barber, but I like the hustle and bustle of a salon. Mariko keeps my very short hair in good order. 30 East 76th Street, New York, NY 10021 (+1212-879 1000; johnfrieda.com)

The last meal that truly impressed me was at Masa in New York. The setting and the food were fantastic and I think this is one of the best restaurants anywhere in the world. Chef Masa is a friend and he takes incredible care of everyone who dines here. His cuisine is always quite varied – he’ll have a little langoustine, a mushroom risotto, some delicious Wagyu with truffles – and it is the unexpected mix that makes eating here exciting. The sushi is also beyond spectacular. 10 Columbus Circle, New York, NY 10019 (+1212-823 9800; masanyc.com)

The books on my bedside table are JK Rowling’s latest, The Cuckoo’s Calling, This Town by Mark Leibovich, which is a fascinating, often funny look at the political world of Washington DC, and The Hare with Amber Eyes: A Hidden Inheritance, a memoir by British ceramicist Edmund de Waal. I tend to mix it up, so I might read a biography and then follow it up with a page-turner. I used to read Dostoyevsky and Tolstoy, but now I stick to contemporary fiction and books related to current events.

If I didn’t live in New York, the city I would live in is Paris. It’s hard to imagine living anywhere but New York, but Paris has some of the best museums in the world; I particularly love the Centre Pompidou, the Jeu de Paume and the Musée d’Orsay. I like walking everywhere – especially around the eighth arrondissement – and eating at ethnic restaurants such as Tong Yen, which has the most beautiful decor. My two favourite restaurants are Le Stresa and Le Duc and when I was awarded the French Légion d’Honneur I had a party at the former. I used to be a resident of the Ritz and look forward to seeing the renovation, but for now I enjoy staying at Le Bristol – it is an easy stroll to my gallery from there. Centre Pompidou, 19 Rue Beaubourg (+331-4478 1233; centrepompidou.fr). Jeu de Paume, 1 Place de la Concorde (+331-4703 1250; jeudepaume.org). Le Bristol, 112 Rue du Faubourg Saint-Honoré (+331-5343 4300; lebristolparis.com). Le Duc, 243 Boulevard Raspail (+331-4320 9630). Le Stresa, 7 Rue Chambiges (+331-4723 5162; lestresa.com). Musée d’Orsay, 1 Rue de la Légion d’Honneur (+331-4049 4814; musee-orsay.fr). Ritz Paris, 15 Place Vendôme (+331-4316 3030; ritzparis.com). Tong Yen, 1 Rue Jean Mermoz (+331-4225 0423)

An object I would never part with is my BlackBerry. I use it to phone, text and email and I find it easier to type on than other devices. When dinner starts, however, I turn it off and won’t check it again until the next morning unless there is something very time-sensitive going on. Although I am particularly attached to this device, I can’t stand it when people check theirs during meals or meetings. blackberry.com

The grooming staple I’m never without is my $1.69 nail-clippers from the local pharmacy. I don’t have the patience to sit still for a manicure, so I carry my own clippers wherever I go.

My favourite room in my house is the library at my beach house. There are piles of magazines and books that I love to read, as well as a ridiculously large television. I have a similar room in each of my homes, but this one has the most relaxed feel. There are comfortable sofas and a coffee table that you can put your feet up on. The whole space feels very laid-back and contemporary.

If I had to limit my shopping to one neighbourhood in one city, I’d choose the Upper East Side of Manhattan, near Madison Avenue. I find everything there, from pharmacy basics at Zitomer to fine furniture from Delorenzo Gallery, whose owner, Tony, happens to be a great friend. I stock up on bathing suits at Vilebrequin and visit Three Guys, the ultimate New York diner, for a casual bite. Delorenzo Gallery, 956 Madison Avenue (+1212-249 7575; delorenzogallery.com). Three Guys, 960 Madison Avenue (+1212-628 8108). Vilebrequin, 1007 Madison Avenue (+1212-650 0353; vilebrequin.com). Zitomer, 969 Madison Avenue (+1212-737 5560; zitomer.com)

If I weren’t doing what I do, I would be unemployed. I’m thankful that I found a job that I love and I’m successful at, so I really can’t imagine doing anything else.