16 GB is a practical mainstream target for many new computers. Choose 32 GB or more when development, large creative projects, virtual machines or unusually heavy multitasking justify it.
8 GB: basic and constrained
Eight gigabytes can still handle light web, email and document work, but it leaves less room for heavy browser use, large office files and multitasking. On systems where memory cannot be upgraded, buying only 8 GB can shorten the useful life for demanding users.
16 GB: practical mainstream target
Sixteen gigabytes is a comfortable target for many new general-purpose systems. It gives browsers, office applications, communication tools and moderate creative work more headroom without dramatically increasing cost.
32 GB and beyond
Thirty-two gigabytes can make sense for developers running virtual machines, large creative projects, advanced photo/video workflows, engineering tools and heavy multitasking. More than 32 GB is usually workload-specific rather than automatically better.
Capacity is only part of the story
Memory speed and channel configuration can affect performance, especially with integrated graphics, but capacity usually has the bigger impact when a system is running out of RAM. Check whether memory is soldered, socketed or partially upgradeable before buying.