Help me upgrade my rig into a gaming beast!

[Danteeva]

Hey, I'm looking at buying some new upgrades for my PC to improve its gaming capabilities, I'm at a point where I have the money to spend on it and make it awesome.
At the moment some of the newer games are beginning to test its abilities, e.g. Fallout 4 has some small frame rate drops, and Just Cause 3 can sometimes blue screen me.
I'm pretty sure my CPU is good for quite some time but the rest I feel may need so work.

Current Rig is:-
Case: Fractal Design Define R4 Silent Black Pearl Case
Motherboard: Gigabyte GA-Z97X-Gaming 3 Socket 1150 VGA DVI HDMI 8 Channel Audio ATX
CPU: Intel Core i7 4790K 4GHz Socket 1150 8MB L3 Cache Retail Boxed Processor
RAM: 8GB (2x4GB) DDR3 1600MHz HyperX Genesis XMP Memory Kit CL9 1.65V
& Kingston 4GB (2x2GB) DDR3 1600MHz HyperX Genesis Memory Kit 1.65V CL9
PSU: Corsair RM 1000W Fully Modular 80+ Gold Power Supply
HDD: 2x Toshiba 3TB 3.5" SATA Desktop Hard Drive (One is at 2TB because I'm dumb and couldn't figure out how to change the setting when I upgraded from 1TB)
OS: Windows 7 Home Premium 64-Bit

Monitors: 2 x Acer Predator GN246HL 24" Gaming 144Hz

So I know that the 980 Ti is supposed to really good, but there are so many makes I have no idea which one is meant to be the best. Any help would be great on that and the rest of the rig would be great
Cheers!

 

[PokerTroller]

This is a Gigabyte GTX 980 Ti Xtreme Gaming OC Edition. http://www.newegg.com/Product/Product.aspx?Item=N82E16814125837 It is completely over kill and sometimes outperforms a Titan X in some areas. It has triple fans and RGB lighting. However, people say that it gets loud. If that isn't a problem for you, it should be fine. Personally, I will prefer a EVGA GTX 980 Ti because I like it's blower style and the green led back lit logo. http://www.amazon.com/EVGA-GeForce-Cooling-Graphics-06G-P4-4992-KR/dp/B00YDAYOJG

 

[Chayan4400]

What you're sorely missing from this build is a boot SSD. It'll make your computer respond at lightning speeds, and will really cut down on boot and load times. You can expect a boot of ~10-15 seconds with an SSD, even with a few start-up programs. Samsung's 256GB 950 Pro is a good choice:

PCPartPicker part list / Price breakdown by merchant

Storage: Samsung 950 PRO 256GB M.2-2280 Solid State Drive ($181.95 @ SuperBiiz)
Total: $181.95
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-04-07 13:44 EDT-0400

 

[Barty1884]

The actual hardware & performance from 980TI's are very similar, with minor clock boosts etc offered by some manufacturers. A lot comes down to design, fans, LED etc.

An SSD as Chayan suggested would be a great addition too! Even an 850 EVO, 250GB SATA would serve you really well, and I believe it's around half the price of the 950Pro. $90 or so.

I don't think I understnad why one of your HDDs are showing 2TB......you can't simply extend the partition in Disk Management?