Sufficient as in "It won't suck", then yes; Sufficient as in "runs like the wind", then definitely not.
8GB is fine for gaming at the moment, but if you've got a dual-monitor setup and you're multitasking on the second monitor, it might cut it a bit short. Chrome uses insane amounts of RAM for no reason.
If you do absolutely no multi-tasking then 4GB might be enough for most games. Most, not all.