20nm is 2014 for Nvidia for sure. Still power bound through 2013.

No 660 TI will not be good enough for Crysis 3 ultra. Crysis 2 is far away from maxing out Cryengine 3 so even if its the same engine this means nothing: 

Crysis 3 recommendations:

MINIMUM SYSTEM OPERATING REQUIREMENTS FOR PC:

• Windows Vista, Windows 7 or Windows 8

• DirectX 11 graphics card with 1Gb Video RAM

• Dual core CPU

• 2GB Memory (3GB on Vista)

• Example 1 (Nvidia/Intel):

- Nvidia GTS 450

- Intel Core2 Duo 2.4 Ghz (E6600)

• Example 2 (AMD):

- AMD Radeon HD5770

- AMD Athlon64 X2 2.7 Ghz (5200+)

RECOMMENDED SYSTEM OPERATING REQUIREMENTS FOR PC:

• Windows Vista, Windows 7 or Windows 8

• DirectX 11 graphics card with 1GB Video RAM

• Quad core CPU

• 4GB Memory

• Example 1 (Nvidia/Intel):

- Nvidia GTX 560

- Intel Core i3-530

• Example 2 (AMD):

- AMD Radeon HD5870

- AMD Phenom II X2 565

HI-PERFORMANCE PC SPECIFICATIONS:

• Windows Vista, Windows 7 or Windows 8

• Latest DirectX 11 graphics card

• Latest quad core CPU

• 8GB Memory

• Example 1 (Nvidia/Intel):

- NVidia GTX 680

- Intel Core i7-2600k

• Example 2 (AMD):

- AMD Radeon HD7970

-AMD Bulldozer FX4150

Next gen is coming soon if he wants to max out all the titles in the next years he better buys the best today. There is no doubt in my mind that the upcoming games will be more demanding than what we saw the last years.

@Soleron

Even within the same stepping alot can be done. AMD 88xx series gets a die increase and 600 Million new transistors keeps same TDP and lowers price. The 680 was quite conservative so who knows what Nvidia is going to do.

OP specified runnig games on highest settings for a few years.  So maybe it would be benefitial to wait for the next gpu gen.

You should go for the Intel i5 3570K. No need for an i7 to game.

Also you cant go wrong with any of these depending on your budget: 7870, GTX660Ti, 7950

It's still going on current gen consoles so I'm doubtful it's gonna be as demanding as you expect. And from what specs I've seen of next gen so far, they're likely going to be budget consoles with budget parts. So the OP doesn't have to go overkill with his comp.

Also GTX 660ti is atm, propably the best value card getting 670 over it is just enthusiast exaggeration as usual.

The difference between 660ti and 670 is about 100$ and maybe 15-20% better FPS in games. So it really comes down to if you want to have 5-10 more FPS for +100$ more. That's why I'd recommend getting 660ti, and investing that +100$ for a superior card in the next few years.

and to put things into perspective even my old 5850 and 955be from 2009 can still max games today without any hitching at 30FPS. Skyrim and Witcher 2 come to mind atm.  :)

Ofcourse if OP has money to splooge, he could allways get more expensive parts for small increases in performance.

Depends what your budget is. For a comparison I will list my build which I did 2 weeks ago.

My build is one which is a great gaming build for running 1080p games at max settings and is also suitable for video rendering if you are into that sort of thing. With this build you will be good for at least 3 years of max setings goodness.

Processor- Intel 3930k processor 3.2ghz 6 cores all duel threaded
Cpu cooler- Noctua DH-14
Ram - 32GB G-Skill 1700mhz
Motherboard- Asus X79 Pro
Power Supply- Seasonic 760W x series Gold
Case - Silencio 650
Video Card- MSI GTX 680 Lightning edition
SSD- OCZ Vertex 4 256gig
HDD- Seagate 3TB Barricuda
DVD Drive- Liteon Blu-Ray Combo drive.

Cost me $2800 roughly. But yeah I think I'm set. If you are just going to use it for gaming though you won't go wrong getting the 3770k quad core and a 1155 chipset motherboard which will save you a few hundred dollars. I got the 3930k because I won't be changing it for at least 5 years so I need my CPU to be as future proof as possible.

Hope that helps. If you need more info don't hesitate to ask.

Get an Nvidia 670 if you don't want to spend too much money

It's awesome, but the magrider is OP at the moment and breaking the server I'm on =(

GTX680 or the AMD equivalent. To be honest the i7 is overkilll and make sure you get a bigger HDD as a backup as SSD's lifespan are dubious. Also if you fill one past 50%  the performance (and again lifespan) declines. 

If you get a PSU and mobo that supports SLI/X fire, then you are laughing for next-gen graphics. 

Quick off topic question if you don't mind. How you finding the DH-14? I'm thinking of upgrading my CPU cooler but can't decide whether air or close loop cooling is the way to go, more so when beasts like the Silver Arrow and DH-14 seem to still give great results. 

That's gonna be a monster computer. Like Godzilla