PCIe 4.0 or PCIe 5.0 for gaming?
For a gaming PC, a good PCIe 4.0 drive is the sweet spot. Drives like the Samsung 990 Pro and Kingston Fury Renegade read at over 7,000 MB/s, and in most games the loading time is limited by the CPU and the game engine long before the SSD. PCIe 5.0 drives such as the Samsung 9100 Pro roughly double the sequential speed on paper, which helps with huge file transfers and some creative work more than with games.
PCIe 5.0 also needs a compatible motherboard slot, usually on newer AMD AM5 and Intel boards, and these drives run hotter. If your board has no PCIe 5.0 M.2 slot, the drive still works but runs at PCIe 4.0 speed.
Capacity: why 2TB is the new 1TB
Big games now take 100GB or more once installed, and Windows plus updates takes a sizeable share of a 1TB drive. A 1TB SSD works for a handful of large games, but a 2TB drive such as the WD Black SN7100 2TB or Crucial P310 2TB means far less uninstalling and reinstalling.
If you keep a large library, a common setup is a fast NVMe drive for Windows and the games you play now, plus a cheaper, larger drive for everything else.
Heatsinks and M.2 slots
Most desktop motherboards include an M.2 heatsink cover for the main slot, so a bare drive is usually fine. Check how many M.2 slots your board has and which generation each supports before buying; the second or third slot is sometimes slower or shares bandwidth with SATA ports or a PCIe slot. For laptops and small builds, check the supported length, which is almost always 2280 for desktop-class drives.