What's the best brand of Nvidia Gtx 780 Ti?

Asus, best and most reputation supplier.

I find that EVGA is the best because they are the only manufacturer to be teamed up with NVIDIA they are in NVIDIAs brand pretty much but think of it this way:
EVGA: for best quality, customer service, and having exclusive versions of each card
PNY: for being one of the cheapest, lifetime warranty, decent customer service, good quality parts
EVGA is better PNY is cheaper and very similar, personally I go with PNY because they are cheaper and really aren't bad at all I would say they are good.

There is no best "brand" as each brand offers several model lines, encompassing 1) reference cards (why bother), 2) factory OC'd cards and 3) specialty cards. For factory overclocked models, outta the box, the best GeForce 780s / 780 Tis come form MSI and Gigabyte with the N Gaming Series and Windforce Series. Once manually overclocked, the Asus stands ahead of the others. The EVGA SC series is at the proverbial bottom of the barrel among factory OC'd cards as the other generally use a custom PCB and beefed up VRM but with the EVGA SC series, it's merely a reference card with a factory OC.

Separate from those however, we have the specialty models......The EVGA Classified and MSI Lightning are in a league of their own a good step above those mentioned above.

I like Asus personally, their DirectCU II cooler generally outperforms the others in temp and sound. Plus, it looks pretty damn sweet.

Here's a roundup comparing 4 of the most popular 780s.

http://us.hardware.info/reviews/4639/10/nvidia-geforce-gtx-780-asus-vs-evga-vs-inno3d-vs-msi-conclusion

Note that the MSI card has been upgraded from a rather paltry 902 Mhz core speed to the current versions which is at 954 Mhz making it a tough competitor for the Asus card.

Here again, w/ the 780 Ti, MSI finished at the top....

http://www.legitreviews.com/nvidia-geforce-gtx-780-ti-video-card-roundup_137646/13

Best clocks, lowest noise.....tho Im sure the Asus will give it a run for it's money, unfortunately it wasn't in the test.

ASUS in my opinion since they have great customer support.

evga easily and they are legendary when it comes to their warranty and support, not to mention they sell 40% of all nvidia branded cards, msi sells 20%, gigabyte sells 20%, asus 8%, and the other leftover 12% is all the other board partners. the evga 780ti classified is by far the best gk110 based board, along with its big brother the kingpin edition. but unless your looking for extreme overclocking under water, any card from those 4 board partners are great cards, acx, twin frozr, windforce, dc2.

i would look into upgrading that i7-950 in the near future as you should see a cpu bottleneck in many newer games with a 780/290 or higher tier.

I went with PNY 780ti OC because it was on sale at newegg for $650. I don't think you can go wrong the 780ti is AMAZING!

I have yet to see a review roundup where the EVGA 780 / 780 Ti SC comes out on top. A card is only as good as it's components and while the EVGA Classified is a fine card, the SC is simply what it is ....a reference card with no distinguishing features other than it's cooler which while rather good does not make up for its shortcomings nor match the performance of the MSI or Asus coolers as described thoroughly in the above reviews.

As for the "legendary support"..... I can only take that to mean 20 support calls, and 5 RMA's and 18 months of hassles before a card meeting advertised specs was provided. They blamed the motherboard, they blamed the RAM, they blamed the PSU but were at a loss to explain why only their card exhibited the problem. The FTW card was advertised with a moderate factory overclock.... about 10 - 12% IIRC. It would run "downclocked" at reference card speeds, it would run at about 2% above reference speeds, but it could not get anywhere near the "out of the box" and advertised "factory overclock" clock speeds

It was replaced three times with and identical card ..... no improvement. Before doing a friend of my son's build, borrowed his GTX 580 (MSI) and it ran fine..... at 21% overclock...... borrowed twin Asus 560 Ti's and they ran fine at a 25% OC. faced with this evidence, they required screenshots, with the 5th RMA .... and in the 19th month of ownership, they finally replaced it with a reference 580..... it's still in use, but....of course running barely above stock speeds.

Also worth mentioning that in each of the 20 support calls it was like it was the 1st time I called. I was required to do the same elementary checks ....open BIOS, read memory speeds and voltages.... yada yada yada on every call. The technician answering the call had no response to "We have gone thru this 17 times already and the previous 17 techs agreed that this was not the problem": It was a good thing I kept a call log as it was only by threatening a call to the BBB that I finally got resolution.

I believe you are making a mistake,
the current gtx 760 sli you have will out perform any gtx 780/ 780 ti on the market

If you dont believe me; check out this video:- https://www.youtube.com/watch?v=KfOtmoxLMXI

I did a lot of research when I was about to buy a gtx 780 ti, I went ahead sli'd my gtx 760. I suggest you do some digging too..
You already have sli 760 so there is no point getting a 780 ti (unless you want to sli 780 ti right away)

You can get a gtx 8XX instead when it comes out.

sli 760s barely beat a 780ti in all benchmarks clock for clock. you need to remember that the reference 760 has a 105mhz advantage out the box, but the average gk110 found in the 780s will overclock much farther than the gk104 found in the lower tier cards. so online tests by reviews don't tell the whole story.

if you only talking a 5-10% increase after average over clocks, clock for clock, its just not worth it over a single card. and remember 3dmark/unigine etc. are highly optimized for sli scaling, in the 95% area. most popular games only realize an 88-92% scaling and some games as low at 70%. the performance lost plus extra power requirements and motherboard requirements, case space and added heat add up to a tricky situation where too many factors make having the single more powerful card a better option.

There are no best. Every company have positive and negative feedbacks. All people here only comment their opinion collected by positive feedbacks and good reputation of the company. Remember every company need to have a chance i like all of them. Every time when i upgrade my rig i go with different brand.

I had a ASUS 780 Ti DC2OC and while it was a good card, the VRM temps would hit 100C which was a bit of a worry, and after reading some reviews seems to be the norm for these cards. I exchanged it for an EVGA 780 Ti which I couldn't recommend enough! It's quiet, quick and cool (the VRM never goes above 60C). Add to that EVGA's brilliant reputation and customer service.

EVGA all the way.