I think being able to record smoothly relies more on having external capture hardware. Either in the form of another computer, or a capture card. Otherwise, you have to record at lower settings, or have lots a lots of hard drive space.
But it really depends on your budget, of course in terms of absolute raw performance, the gtx 690 will be the highest, but the gtx 780 will be cooler and quieter, and the gtx 680 alone would be the cheapest. The gtx 680 will still be adequate for quite a while though, unless you really need the extra performance afforded by the 780 or 690. The gtx 690 is better value than a gtx 780 though.