That’s a tough question to answer because there are a bewildering array of PCs and Macs out there, and things can get super complicated and in-depth if you are someone who wants the fastest, most cutting-edge RAM in order to squeeze the last drop of performance from your system.
Swapping RAM in most PCs (even laptops) isn’t that hard, but finding the right RAM can sometimes be challenging, especially if you aren’t familiar with the specs and what things like DDR or speed mean. If this is you, I recommend that you check out RAM suppliers such as Crucial or Kingston. These sites will guide you to the right RAM for you.
As for fitting instructions, the web – in particular, YouTube – is full of great information. Rest assured, replacing RAM is the easiest upgrade you can do.
But, if you are a bit more comfortable with knowing what ARM you need, I’ve pulled together a compilation of my favorite RAM. This is hardware that I’ve tried and tested and offers great performance and value for money.

64GB (4 x 16GB)288-Pin DDR4 SDRAMDDR4 3600 (PC4 28800)18-19-19-39 timingsCAS Latency 18RGD lighting

Things don’t get much better than this! Super-fast RAM modules, super reliable chips thanks to Corsair’s excellent quality control, and super stability thanks to testing and excellent heat spreaders. And also, cool LED lighting, which is fun, right? This RAM is not cheap – you’re looking at around $400 if you want 64GB of high-speed RAM, but you will be getting the very best out there. Pros:

Tons of memoryRGB lightingDual-channel cooling

Cons:

Expensive

32GB (2 x 16GB)288-Pin DDR4 SDRAMDDR4 3200 (PC4 25600)16-18-18-38 timingsCAS Latency 16Compatible with AMD 3000 series

At the more restrained end of the performance (and price) spectrum we have the G-Skill Trident Z RGB. I’ve fitted (or recommended) this RAM into dozens of gaming system, and never had a word of complaint. Highly rated RAM, and a firm favorite of mine for gaming systems. Pros:

AffordableLots of memoryRGB lighting

Cons:

May not be compatible with older CPUs

16GB (1 x 16GB)288-Pin DDR4 SDRAMDDR4 3200 (PC4 25600)Timing 16-18-18-36CAS Latency 16

We’re now into what I consider “mainstream” RAM. This is RAM for everyday systems. Systems that will run day in, day out, where I’m not concerned about benchmarks or tiny speedbumps from having the fastest RAM possible. It’s hard to go wrong with Crucial Ballistix. It’s the RAM that I use and recommend for systems where reliability is more important than performance. Pros:

Very affordableWorks with AMD and Intel CPUsAluminum heat sink

Cons:

Not as much memory as other options

16GB (1 x 16GB)SO-DIMM 260-pinDDR4-2666 (PC4-21300)

If I’m buying RAM for Macs, OWC is the brand I go for. Yes, you can buy cheaper, but it’s hard to buy better. The advantage of dealing with OWC is that this is a company that knows what works in which Mac and makes no-compromise RAM that is 100 percent compatible. The company even has DIY install videos to make the upgrade as painless as possible. Pros:

16GB option under $100Compatible with older Mac modelsDIY videos available

Cons:

Pricey at higher capacityNo heat sink

16GB (2 x 8GB)DDR3 1600MHz ( PC3L-12800 / PC3-12800)

I want to call this budget RAM, but that doesn’t do it justice. You’re getting good quality RAM modules at a sensible price. Timetec offers a good selection of RAM modules – desktop, gaming, laptop, server, and Mac – at a price that’s hard to beat. This is the perfect RAM for dropping into a system and forgetting, and a great choice for upgrading an older system. Pros:

Very affordableDecent memory capacity

Cons:

Older RAM modelNo heatsink

If you are building a new PC, I always recommend checking the with motherboard manufacturer for what RAM is recommended (I highly recommend doing this if you plan of overclocking the RAM in a performance system). For most applications, budget RAM from a reputable vendor is the ideal choice, offering the best bang for the buck. All product specifications have been provided by the manufacturer and are correct at the time of publication.

Budget RAM: I chose these options because they deliver the best possible bang-for-the-buck while still delivering stable performance.High-performance RAM: I added stress and overclocking testing to check that the RAM remains stable when pushed to the limits, something that is important in high-performance PC builds.

RAM tips

16GB (2 x 8GB modules) is the sweet spot in terms of price and performance.Mixing and matching different RAM is a recipe for problems.If in doubt, check the specs of your system with the manufacturer of the system or the motherboard.