If you paid an extra £50 or even £100 for a more expensive model from a specific brand, will you get a more reliable washing machine? No. You'll get a bigger drum, faster spin, and more options, but the build quality will almost certainly be the same or not substantially different.
Manufacturers usually produce a range of washing machines built to sell and compete in the price range they are pitching at. The differences between their basic, and their top models, which could be hundreds of pounds, is in features. There is usually little or no difference in quality between their basic model and their top model.
If you want a better quality washing machine, you need to choose a better brand.
Example: Miele’s entry level washing machine is considerably better quality, could last 2 or 3 times longer, and will be much quieter and more reliable than Hotpoint's top of the range washing machine – but they are pretty similar in price. The difference will be that the Miele is far better built but the Hotpoint (or other brands in same price range) will have a much bigger drum, faster spin speed etc.
Manufacturers make a specific quality of appliance and create dozens of variations
The important thing to understand is that specific brands of washing machine (or any appliance) tend to be either budget, middle of the road, or more rarely, high quality, and all washing machines within their range are built the same standards (even sharing most parts).
Most manufacturers like to compete in more than one price range, but they do it with different brands. So for example, Bosch appliances are at the budget to lower mid price range, but the company which owns them also own Siemens and Neff branded appliances, which are not only higher spec, but in a higher build quality (and price) range. The same goes for AEG and Zanussi, with AEG being the higher spec and slightly better build quality brand, both owned by Electrolux.
With budget washing machines you could even argue their most basic model is probably better
The worst quality washing machine manufacturer can still produce a souped-up model in the latest fashionable colour. It will spin way too fast for the build quality of the machine and bounce around the kitchen because the suspension is cheap – but the washer could still expensive because of the perceived value of its features. If you take out an extended warranty too, you can end up paying out more money for a rubbish washing machine than for a less specified but high quality washing machine which would last much longer. Decide whether to spend your money on a more basic but well made washing machine, or on a washing machine with a faster spin and bigger drum that's potentially unreliable and noisy.
Compare the basic entry model of each brand of washing machine you are interested in. So if you see a £500 washing machine, but they do a basic model at just £290, you know that the £500 washing machine is likely to be built to the same build quality as the £250 washing machine, the rest of your money is going on features.
Ideally, if money's no object then a washing machine that combines higher spec and quality is best, but if money is tight then a basic cheap washing machine may have to do. I just think too many people are paying over £600 out for washing machines that are not higher build quality but but just have bigger drums and faster spins, when for the same money they could buy a better quality one with less features.
Finally: Don't go on looks. The highest quality washing machines are rarely the most "attractive" (often expected to go into wash rooms) and the ones that look the nicest, are often not as well made.
For personal recommendations (so far) see
What’s the difference between most modern brands of washing machine?
Build quality wise? Virtually nothing. I’ve stripped down many brand new washing machines recently and laid all the parts side by side. I was astounded at how virtually all parts are the same quality, same design, and clearly made in the same factories. They all look virtually identical inside. You might as well just pick which one is prettiest. The main significant difference between most brands (except Miele who are still head and shoulders above the rest) is their quality of aftersales service, availability of technical support, availability and price of spare parts, how long they guarantee the product for, and how repairable they are. Most of these significant aspects are never mentioned in reviews .