suggest me a power efficient gaming card

On a budget...

full disclosure:

I have a matx cube that i use to play movies/tv shows and double as a gaming "console" for my tv (this guy is for lighter duty gaming/psx emulation/doing my WoW garrison missions from the bed etc).

current setup is an a10 apu with ddr3 2666 doing hybrid graphics with a 7750.
this setup works well but the box was originally low profile before moving to the cube, which allows me full height cards and better cooling.

Ideally I am looking for a card that will outperform this setup but draw the same or less power. this unit is basically on all the time as background noise (especially now that the gf works from home). so something that can lower its idle draw or be efficient in draw when doing movies then ramp up when actually being called to game would be ideal.

I've been doing home work, but there are a lot of cards out there when you open up the full spectrum of mainstream cards, so any suggestions would be appreciated.

GTX960 ?

My wife has one in here mini ITX setup and plays WoW at 1920x1080 with all settings maxed out.

Yup, GTX 960. Low power, high 1080p performance. Basically, it's faster than any other card at the ~$200 price point (short of a ~$275 R9 290, which consumes twice the power).

Also, they have two PCB lengths. The majority of the cards are long, but the Asus STRIX is short, and just as quiet and overclockable as the bigger cards.

http://www.newegg.com/Product/Product.aspx?Item=N82E16814121913

It's on sale for $187 until the 30th

I'm a happy owner, and can max-out all my current games at 1080p. And It can even do a pretty respectable job with GTA V, the new king of the hill:

http://www.hardocp.com/article/2015/04/27/grand_theft_auto_v_single_gpu_performance_review_part_1/4

yep, I was afraid that was gonna be the answer

seeing as the 750's are basically the same as what i have now with a small power drop.

I'll watch it for a price drop as we go forward as it's not an immediate necessity. though at least i have something to aim for.

thanks!