Adata is one of the best brands for budget RAM, and their long-standing Gammix D10 series offers a good balance of low price and high performance. Right now you can pick up two 8GB sticks of DDR4-3200 CL16 memory from Ebuyer for £56, around £10 cheaper than you'd pay for RAM with the same specs on Amazon.
If you're building a new PC or upgrading an old one from DDR3 to DDR4 (with a motherboard swap, obviously), then this is pretty much the best value spec available. There is faster and lower latency RAM, to be sure, but generally you're paying more than you're getting back in extra performance.
One thing that trips up some newcomers is that it's very important to be running dual-channel memory, e.g. two 8GB sticks rather than one 16GB stick, as running in dual-channel mode provides a big boost to performance. You can also use four sticks of RAM, but consumer-oriented motherboards don't offer a further speed advantage for doing so - you'd need an Intel X-series motherboard or AMD Threadripper system to get proper quad-channel RAM support.
This particular RAM is a good choice because it offers the specs you ned at a low price, but it also includes a heatsink - which is potentially useful for overclocking and it certainly looks cool too. Thankfully, it's not a very tall heatsink (7.5mm tall), so it should be able to fit under most CPU air coolers.
I hope this deals alert was useful; thanks for joining us and stay tuned for more deals in the very near future!