What is better for gaming?
What is better for video-editing and rendering (I use Sony Vegas Pro and After Effects)?
Which is better for both?
Which is better overall?
i3-3220 costs about 6$ more than the Phenom. Phenom II X4 has 4 true cores which could be handy for Sony Vegas and After Effects but will I see any difference from the i3-3220 which has 2 cores and 4 threads? Phenom II X4 has no L3 Cache and has very very old architecture, but then again, its 4 cores weighs very big on my decision-making.
"Noticable" difference? Eh, not really, but it's certainly a measurable one. It could be noticeable if you were at 30 FPS minimum with the 3220 because that would mean something like a 20 FPS (or a little less) minimum with the 965, but with a good enough GPU, that won't really be much of an issue.
As far as video editing goes, actual cores are king. The 2 HT "cores" of the i3 are about 1/3rd as powerful as a real core.
The PII should be fine at Ultra settings in Crysis 2, since you're gonna run into a GPU bottleneck, at that point. It won't be "great", but it'll do.
High resolutions and maxed out (or close to) quality settings will always be worse on the GPU than it is for the CPU. Almost any modern CPU will do reasonably well given those conditions. If you're forced to lower the res and the quality settings because of an inadequate GPU (or a monitor that isn't higher res), that's when a slower CPU hurts you.