Yes, a very good one.
I dont think any single GPU card can do that yet. Maybe the new 980ti. But at higher resolutions even that one will give in.
If you use a standard 1080p screen, with a single GTX970 card you will be able to play with everything on ultra.
Provided the rest of your system is fast enough too. (W3 stresses the CPU just as much as the GPU).
You will get FPS as low as 40 or mid 30s in some areas on ultra settings.
Some people dont mind that. Some find it unacceptable.
EDIT:
If the rest of your system is slow, the card will not help you!
Post your current system specs if you want serious recommendations.
I play resolution 1980x1020 1080p
Anyway i buy new pc (september/october) and have this:
Case PC: Aerocool Strike X ONE Army Edition
CPU: AMD X8 FX 8350 4.0 GHZ
MoBo: AsRock 970 Extreme3 R2.0
GPU: NVIDIA GEFORCE 970GTX 4 GB GDDR5
Power Supply: iTek mPower 820W
RAM: 8GB DDR3 CORSAIR VENGEANCE 1600 MHZ (+ have in my actual PC, 4 GB RAM
2x KINGSTON - DDR3 4GB 1600MHZ CL10 DIMM FURY HYPERX SINGLE MODULE)