In a world of constant rebranding and relentless upgrades, it's reassuring to know some of our favorite branded products have stayed the same for decades. Boasting outstanding design, these iconic favorites just can't be improved any further, or so we think anyway. 

Read on as we take an admiring look at popular products that can't be bettered.

Based on László Bíró's 1931 invention, the Bic Cristal pen was launched in France in December 1950 by entrepreneur Marcel Bich and has gone on to conquer the world. By 2006, a staggering 100 billion Bic Cristal pens had been sold and the design of the pen remains untouched to this day.

A fixture of countless upscale kitchens, the classic Aga range was invented in 1922 by a Nobel Prizewinner, the Swedish physicist Gustaf Dalén, and has been in production ever since. While electric and eco models are now available, the fundamental design remains unaltered.

Staying in the kitchen, the KitchenAid mixer is another iconic product that has stood the test of time. The mixer was updated in 1937 by industrial designer Egmont Arens and is still made to more or less the same specifications.

The modern Lego brick design was patented on January 28 1958, and has remained unmodified since its introduction. In fact, Lego bricks manufactured in 1958 interlock perfectly with bricks made in 2020.

Ray-Ban has introduced variations on its Wayfarer design over the years, but the classic sunglasses model hasn't changed since 1952. The design has been popular for decades, worn by Hollywood stars in the 1950s and hipsters in the 2020s alike.

The world's best-selling chair, millions of Hille polyprop chairs have been sold since the product was launched in 1963 – just think how many times you've found yourself sitting on one. The ubiquitous chair is the handiwork of Robin Day, the UK's most celebrated 20th-century furniture designer.

These clever little adhesive notes were invented by 3M scientist Spencer Silver in 1968 and launched as Post-it notes in 1977. Never bettered, the design of the notes remains untweaked to this day. 

The UK's national traffic light system was redesigned in 1965 by David Mellor, who also designed stainless steel cutlery and bus shelters, and German industrial giant Siemens has been making traffic lights to Mellor's exemplary design ever since.

Dubbed 'the pinnacle of record player design', the high-end LP12 turntable was introduced in 1972 by Glasgow-based firm Linn Products and remains the gold standard record player for audiophiles – no other turntable can match its exceptional quality.

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The Dr. Martens boot was invented by German soldier Klaus Märtens in 1945 and marketed in the UK from 1959 by shoe manufacturer R. Griggs, where it soon garnered icon status. Doc Martens are now available in a variety of colors and finishes, but the basic design is identical to Klaus Märtens' 1945 prototype.

The world's most iconic style of blue jeans has remained more or less unchanged since its launch way back in 1890. The quintessential pair of denims, the Levi's 501 style has seen off trend after trend, thanks to its timeless, enduring design.

A kitchen essential for over a hundred years, the heat-resistant Pyrex Classic measuring jug was invented in 1915 and still sells by the truckload. Brimming with quality, each jug is guaranteed for 10 years. 

The Gucci of espresso machines, the Faema E61 was launched in 1961 and hasn't been bettered. Renowned for making the perfect espresso, the top-end machine retains the same design to this day.

Its innards may have been tweaked, but the basic design of Klipsch's flagship Klipschorn speaker hasn't changed since it first hit the market in 1945. The much-coveted speaker is lauded for its room-filling sound quality.

The world's first commercially successful solid-body electric guitar and the instrument that made the pop and rock music of the late 20th century possible, the Fender Telecaster has been around since 1950 and still sells like hotcakes.

The archetypal desk lamp, the Anglepoise 1227 was created in 1932 by British car designer George Cawardine and launched in 1935. A bona fide design classic, the 1227 remains super-popular to this day.

Weber's George Stephens invented the famous dome Kettle grill in 1950, which is still a bestseller. A former buoy designer, Stephens chopped a metal buoy in half to make the barbecue and the rest is history.

Living up to its name, Hardy's Perfect fly reel was invented in 1891 by brothers William and John James Hardy in Alnwick, England. Widely regarded as the ultimate fishing reel, the much sought-after Perfect is still in production.

The original biker jacket made famous by Hollywood legend Marlon Brando, Schott's Perfecto Model 118 has inspired myriad imitations since its launch in the late 1940s and is still available to buy today. 

French firm Le Creuset has been churning out its round Signature casserole since 1925. The cast iron cooking utensil is prized among amateur cooks and top chefs alike, and continues to sell in high numbers. 

Kikkoman is certainly a stickler for tradition. According to the Japanese company, the recipe for its superior soy sauce has remained unchanged since the 15th century and the design of the classic smaller bottle hasn't been altered since 1961.

Campers wouldn't be without their trusty Petromax HK500 paraffin lamp. Still rocking its 117-year-old design, the indispensable lantern was created in 1910 by German inventor Max Graetz.

London-based company Brompton invented its indomitable folding bike in 1975 and, while the firm has launched super-lightweight and electric versions, the superlative design of its star product remains unchanged.

A common sight in kitchens the world over, the eye-catching Dualit Classic toaster was designed by German-born inventor Max Gort-Barte in his London factory in 1954, and has gone on to sell in the millions.

Converse created the precursor to the perennially-popular All-Stars shoe in 1917 and basketball player Chuck Taylor improved upon the design in the 1920s, which has stayed virtually unchanged over the years.

Hire an Uber and it's likely you'll spot a forest of Little Trees air fresheners hanging from the rear-view mirror. Invented in 1952 by chemist Julius Sämann, these handy air fresheners have been making vehicles smell good for decades. 

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Now take a look at some product changes and rebrands that flopped spectacularly