HTPC / gaming build

Even your midrange is high end by this forum standards.

What's your ideal budget ?

Well my first thought is you list an 3470 and a 3770k CPU. Why not go in the middle with 3570k?

It's cheaper than 3770k and faster than 3470. At least for me in the US it's usually a better value too but if your ability to find a value is different where you are I'd just get whatever makes sense.

Any i5 or higher is going to be appropriate to game with a video card.

You list nvidia over AMD. Is that because nvidia performs better on games you expect to play ?

Another question... You list some high end motherboards but your not planning to use dual video cards or some of the features they have.

You might want to check out an AsRock z77 like the 3/4 pro or extreme which is only about $100 US.

Unless you need the PCI lanes for SLI or Crossfire video cards, or need 10 SATA ports I think they would be a better fit for you and save some cash.

I don't think you need a core i7 for gaming, every system I have seen is graphics card limited and you definitely don't need a core i7 for HTPC. I would consider the core i5 with the GTX680 a high end gaming machine, not sure you will see any speed bump in gaming by going with 16gigs of ram over 8gigs.

Pretty good advice.

For your higher end model you could drop the PSU down to at least 650W (or possibly 560W) even with the GXT680. NVidia's 600 series cards have significantly reduced power consumption.

i5-3570K is adequate for gaming. An i7 only gives 2-3fps more on most games. Even though you're not intending to overclock, I suggest you still go for the K-series to give you that option later for minimal extra cost.

Coarsair H80 can be a little noisy and most people generally swap the fans for Scythe Gental Typhoons or Noctua NF-F12-PWM fans to get the noise down. Even then I've seen a lot of posts about the pump being noisy. Depends on the luck of the draw. Have a look at the Noctua NH-C12P SE14 instead. It's doesn't look as nice inside the case as a H80 but then you don't have a window on the case anyway, it about half the price, performs within 1-2 degrees and is quieter.

For the high-end case, do you really need a touch screen? Some people swear by them while others find them a hassle or distraction.

I don't know which Kingston RAM you're looking at but choose low profile RAM instead of RAM with big heat spreaders on it. The heat spreaders are only for show and limit your options if you want to but an CPU cooler on later.

If you do go for a GTX680 look at the Asus Direct CU II, Gigabyte OC or MSI Twin Frozr OC. Their coolers have better acoustic and thermal performance than most other reference cards. The GTX660Ti is still a very good card for 1080p gaming. GTX670 if you want to sit in the middle. All these cards can be easily overclocked for minimal extra noise if you need to get a bit more grunt later. I'm more familiar with Nvidia than ATI so will leave for others to discuss their cards.

To power on/off from S4 or S5 state you need a motherboard with a CIR connector for the IR receiver. A USB IR receiver will standby to and resume from S3. The advantage of going to S3 is that the PC will automatically resume and sleep for scheduled tasks and recordings.

It's easier to sleep/wake the HTPC than to completely turn it off and on. If really want to though, there are some options. I've personally tried #2 and #4, and they work perfectly fine.