Do you love movies and TV in general? Do you have gear that can play UHD with HDR or possibly DolbyVision? Are you paying Sky or Virgin for UHD quality and their UHD downloads?
Where the answer is yes to any of these questions then for a grand an LG OLED will rock your world, even at 55".
The 55" is currently at the sweet spot for price and performance. If you want to get the most out of UHD sports channels and the higher-quality streaming services then all the features you don't yet know are crucial for this are all in the 55" OLEDs: 10bit panel, 100/120Hz refresh, wide viewing angle with no colour change, far deeper black and astonishing contrast compared to LED/QLED sets. Really good motion processing. Low lag for gaming.
You won't get all that in a £1,000 LED/QLED set at 55". You can have pretty decent blacks but poor viewing angle, or a wide viewing angle but washed out blacks. It could be a toss-up between 100Hz panel or full true 10bit colour rather than fudged 8-bit dithering (8+2 FRC). As you go bigger for the same budget then many of these features will also drop away.
The advantage with an LCD-based set is the possibility of it being brighter, so that's good if your room gets lots of natural light. But honestly, even that's a bit of a scarce feature as the panel size gets bigger.
By the time you hit 75" for a grand the TV will be a bit mediocre if I'm honest. The thrill of a much bigger screen is a tough temptation. But are you prepared for almost no step up in brightness for HDR, and for poor motion processing and artificial- looking colours?
Unless you have a really bright room, or you sit so far away that 65" or 75" makes perfect sense then get the 55" OLED.