If you're going to play on a 4K resolution then yes, you'll need 4 GB. Also some 'old' (now) games still requires more than 2 GB of VRAM at some instances, most notably - Star Craft 2.

I have said this in another post but I love my R9 390x Black edition. fantastic card and a damn good upgrade from my 5770

Sorry to say, but the most important information you haven't posted ;)

Which games to you want to play?

The newer ones are already easily eating up 4 GB, but if you play 'older' games ONLY 2 GB is sufficient.

And also which colour depth do you prefer?

If you can still wait a bit, I would suggest, wait a bit longer as there seems to be quite some fluctuation possible in the moment, one reason being AMD release a new card with HBM-memory.....

Better cards also compute better. I'd look into the r9 390 8gb just to be futureproofed, You'll be ahead of the curve. :)

And they have 2GB graphics cards (I believe.) So 2GB could be good for gaming on a game's minimum settings (I have a GTX 750 Ti at the moment and it does what I want it to do.) Better settings on a few games now and most in the future would probably need 4GB though.

In this day and age never go bellow 4gb of Vram on any card, and if you wanna go in the future proof zone than hit up 6gb but get a really high end card that will support that in the coming years.

but yeah 2gb is not going to cut it with modern AAA and more upcoming games. unless you are planning to play a lot of older games from latest of 2014 and nothing past it if you are planning on going full ham and max everything out extreme/ultra.

Consoles usually does not require the power of a PC for the same results because optimization of a closed platform. XB360 specs read at best as a low end gaming PC from 10y ago.

https://en.wikipedia.org/wiki/Xbox_360_technical_specifications

Considering the modern console specs we can expect absurd jumps in gaming quality (visual & audio; good game-play is an entire different topic and no hardware monster can fix that).

edit: Yeah. Future games. Or oddity's like StarCitizen (assuming it gets released). Current development still has to consider ongoing development from before new gen. console releases & dual releases for last gen consoles since still a lot of users.

For casual games (read: Non yearly titles) 2GB will be fine, AAA games the likes of Battlefield, Assassin's Creed, GTA V, Shadow of Mordor, Far Cry and Witcher 3 will fill it up (or come very close to) very quickly.

Also remember, the higher resolution you play in the more VRAM will be used so keep that into consideration. While nothing is futureproof, a 4GB card will definitely serve you longer.

Thank you all for the great info. A little more detail from me to cover some of the questions asked.

What age games do I play?
I never buy PC games new, I usually wait until something is old enough to drop in price or go on sale, so much like the hardware, the games are usually last year's model at the newest.

What kind of games do I play?
Not casual games. Mostly RPGs and strategy games, but my son also uses this PC and he is FPS action all the way.

What resolution/color depth/etc. do I use?
The highest resolution I will be playing at is 1080p, 32 bit color. I have no interest in 4K, 8K, UltraHD, Superduper Xtra HD or anything higher. I sit at a desk with a 22 inch monitor less than a few feet away, those higher resolutions are meaningless to me. If I ever need to replace that monitor, it will not be anything significantly larger than what I already have and will max out at 1080p.

ATI/AMD or Nvidia?
I will never, ever buy ATI/AMD hardware of any kind, so please don't bother suggesting them. Nvidia graphics are the only choice for me.

Budget?
Flexible, but maxing out at about $250-$300. Most of the 2GB cards I've been looking at are right around $200.

Witcher 3 uses up to 100% of the 12GB VRAM I have at 3840x2160. Plenty of games use 4. Almost anything new that's super shiny will happily let you use HD textures chewing up 4GB.

That has more to do with your setup than the game itself. On a more standard, single monitor, single card 1080p setup, it reportedly only uses up to about 1.5GB of VRAM on its ultra settings. However, it should be noted that Witcher 3 is far more optimized than most PC games these days.

Yes, I know. But even highly optimized games will chew through VRAM if you play on very high resolutions with dense textures. At no point was I saying Witcher 3 is greedy. But to answer the OP question, is there a point to getting a card with more VRAM, yes there is if you're going to play at high resolutions. And to correct darthspudius' claim that games don't use 4gb, figured I'd give an example of RAM use on a brand new game at the highest supported settings.

I thought I included enough information in that post to make that clear; since it seems I didn't, good on you for adding detail.

Yes, but not as much as you'd think. Full HD uses just under 8 MiB per buffer; 4k would use 32MiB each. There are usually at least 2 frame buffers, so that's 64MiB. Plus, deferred shading is popular these days and that introduces lots of other buffers, although these not always have to take up as much space as a frame buffer. So 4k would probably eat up 100-300 MiB - not tiny, but a 2GiB card shouldn't break a sweat. Textures are complicated - you'd end up seeing higher detail textures but for... reasons... this wouldn't necessarily affect memory usage or performance at all.

Memory matters. If you have enough then adding more won't do anything, but if you have too little then adding more can have an enormous effect. However, the main resource that you need to worry about at high resolutions isn't so much memory - it's shader units. You want as many shader units as you can possibly get.

OK, you would be fine with any 2 GB-card ;)

But now (sorry have to ask) what is your son playing, or in other words, is your opinion, my PC, my rules? If so, just go with 2 GB as most newer games would still run more than adequate on 1080p and a slight drop in FPS can be most of the time being countered with a slight drop in quality.....Maybe this way your son will appreciate also more good old games ;)

As you don't like AMD:

Geforce GTX 960? (available as 2 and 4) Would be in your upper limit but me thinks would more than satiesfy your needs ;)