Let's start with what you actually
need. That's because broadband providers like to make you think that faster speeds are automatically much better but that's not necessarily the case for many people.
If you live in a house full of teenagers, nearly all of whom will want to be watching video streams, or playing the latest online video games, simultaneously, then you might well need a reasonably high download speed. However if, like me, you live on your own and just use the internet for casual web browsing and, say, watching something like Netflix, BBC iPlayer or Now TV in standard definition, you'll not require fantastic speeds.
I'm using an old-fashioned ADSL connection that gives me just 10 Mbps. However that's nearly twice what I actually need just to watch Now TV or BBC iPlayer, plus some casual web browsing. So (apart possibly from being able to download large files a bit quicker or to upload long videos to YouTube somewhat faster, both of which I hardly ever do anyway), I'd gain absolutely nothing from having a faster broadband speed. If I had, say, a speed of 50 Mbps (or greater) the only difference it would make to me would be a bigger hole in my bank balance.
To watch, say, Netflix in high definition (HD), the recommended minimum download speed is a mere 3 Mbps (although I'd suggest that 5 Mbps might prove to be little more reliable). To watch Netflix in full HD (FHD), the minimum recommended speed is 5 Mbps (but I'd suggest 8 Mbps as a true minimum for reliability. Watching in ultra HD (UHD) nominally requires a minimum of 15 Mbps (but I'd suggest 20 Mbps for a reliable service).
So, if you're on your own, it's highly unlikely that you need anything greater than 20 Mbps. Higher speeds will simply mean higher prices and absolutely nothing else.
Having got all of that out of the way, I'll point you to the Money Saving Expert website, so that you can seek out the best deal for your needs:
https://www.moneysavingexpert.com/compare-broadband-deals/?feature=socialtariffs