Start with John Lewis. They don't stock the complete and utter rubbish, and their prices are within 20% of the best that you can get.
Avoid Korean fridges and washing machines like the plague. Although they have attractive warranties you will need to use them and they're not manufacturer warranties, they're just insurance policies with generic toms dicks and harries doing the repairs.
Avoid fridges and freezers with whizzbang features. No icemakers. No water features. They will break. It's worth paying for a frost-free fridge though IMO. Avoid American style jobbies. Buy two separates instead. Avoid built-in. Make sure that you can open the bottom drawer easily. Cheap ones you need to open the door past 90 degrees to get the bottom drawers out. Better ones roll out (on bearings) with the door at 90 degrees, so you can still use it even with the fridge in a corner.
Washing machines take hammer. You want warranty. Tumble dryers also. Again avoid whizzbang features. Worth paying for machines where you can open the door partway through the cycle (sock mode!) and for a decent size (7 or 8 kg nominal) machine so that you can do a duvet in it.
Dishwashers. Buy one that has 3 drawers - a tray just for cutlery - as they're a joy to use.
I ended up buying All Siemens, all white, and all from HiSpek in St Albans. Siemens rather than Bosch or AEG as they had a cashback and 5 year warranty offer on at the time, and HiSpek rather than John Lewis as they offered 0% finance for 12 months. 2 giant fridge freezers, 1 dishwasher, 1 washing machine, 1 tumble dryer, 2370 the lot. (1870 if you just wanted the one fridge-freezer; I've got two side by side as an american style) Not cheap, but not outrageous, and should anything go wrong there's just one number to call to make it go away for the next 5 years. (Siemens)
FF: (was 625-100)
Buy Siemens KG39EAW40G iQ100 lowFrost Freestanding Fridge Freezer with FREE 2 Year Warranty (via Redemption) online, £669.00 Kitchen-Home-Appliances-Refrigeration-Fridge-Freezers - Hi-Spek
DW: (was 530-75)
Buy Siemens SN25M280GB 60cm Dishwasher in White with FREE 2 Year Warranty (via Redemption) online, £529.99 Kitchen-Home-Appliances-Dishwashers-Freestanding-Dishwashers - Hi-Spek
WM: (was 530-75)
Buy Siemens WM14Q390GB iQ300 varioPerfect 8kg 1400rpm Washing Machine with FREE 5 Year Warranty (via Redemption) online, £564.00 Kitchen-Home-Appliances-Laundry-Washing-Machines - Hi-Spek
TD: (was 404-75)
Buy Siemens WT36V395GB iQ300 Vented Tumble Dryer with FREE 5 Year Warranty (via Redemption) online, £454.00 Kitchen-Home-Appliances-Laundry-Tumble-Dryers - Hi-Spek
Bosch/AEG make equivalents, I would wait until one or the other has a good manufacturer cashback/warranty on in your shoes then get the lot in one hit - as when they have offers they really are offers.
Alternatively... ...factory approved seconds. I very very nearly bought these and was umming/aaahing when the Siemens offer came up. You will get a full 5 year warranty from AEG on the WM/TD, in addition to the 1 year warranty from the retailer. They are individually graded and priced, so if you're prepared to accept a scratch on the door rather than the side panels you can have that washing machine for 299 etc. Very quiet machine again worry free for 5 years. Worth visiting his physical shop as they have far more in stock than is listed on eBay. (eBay tends to be the stuff that doesn't fly off the shelves by itself)
AEG L75470FL Freestanding 'A+++' Rated 1400rpm Spin 7kg ProTex Washing Machine 7332543126897 | eBay
AEG T65170AV Freestanding White 7kg Reverse Action Vented Sensor Tumble Dryer | eBay
AEG S83800CTM0 Freestanding 'A++' Rate Frost Free 2m Tall Upright Fridge Freezer | eBay
Cookers? Induction hobs + microwave combi ovens IMO:
These maxisense induction hobs. As fast/responsive as gas; but dead easy to clean and and be used as a normal worksurface when not in use. Pay 350 ex display or 200 for one with a chipped corner (a dab of black silicone will make it disappear) Three rings that you can fit ANY pan on are more useful than four rings that you can't fit four pans on IME.
AEG HK953400FB MAXISENSE 90CM INDUCTION ELECTRIC HOB (BRAND NEW EX DISPLAY) | eBay
These Sharp microwave combi ovens. Buy two and you can have two microwaves, two grilles, or two ovens as required. They warm up MUCH faster and use less energy than most "normal" ovens and the temperature control is better, though the grille is quite small. Microwave base is ceramic and works extremely well as a pizza stone too. Looks like a microwave and you would think it is small but no, these are BIG. 40 litre. Will just about do a goose. The veggies have to go in the other one though! I bought three and have one left as a microwave and two set as ovens.
Sharp R959SLMA Open Box Microwave With Grill 40L Express Cook Defrost Timer 900W 4974019526355 | eBay
Built in with a piece of MDF/some good paint, or hacking up a kitchen unit door (they're 55 cm wide, so fit any "fridge" or "oven" kitchen unit, and are suitable for stacking with their intake/exhaust arrangements) they look an awful lot more expensive than they are. The mother mocked, but prefers my setup to her built-in Neff rubbish at 3x the price. EXCEPT for self-clean. They don't have this unfortunately.
If you're patient, find an old Panasonic Dimension 4 from the late 80s. These had all the above features PLUS a weighing scale, so you just slammed a chicken in and pressed "chicken" - it weighed it and worked out the cooking time perfectly each time. Not popular though (women felt insulted by it, men didn't buy appliances) so they were withdrawn from sale fairly quickly.