The first step is to physically locate the PC near the display and to make sure that it can be connected. This can be difficult if the PC or the TV were not made during the same time. Adapters can be used to convert signals, for example, it's possible to buy a video converter which converts an HDMI port output to an S-video input.
As with any cable purchase, digital cables either work or they do not. Therefore items marketed as being gold-plated are no more effective than standard cables. Analogue cables have more variation. In most cases, the average consumer will not notice a difference between premium and standard analogue cables.
HDMI:If you are using HDMI, then you are already set up for audio
VGA / DVI:If you are using VGA, then you can either use Optical or a 3.5mm auxiliary cord
Optical / S/PDIF:If at all possible use optical audio out for near bit perfect output to a receiver or wireless headset, This is preferred if you have a nice sound card/on-board audio.
Adding a USB panel to an empty drive bay can be advantageous, even if your case already has USB ports on the front. It assures that you have convenient ports for plugging in controllers and other devices, which is important if the rear of your PC is inaccessible in an entertainment center. It also adds a degree of protection. It is not uncommon for someone to accidentally pull on a controller's cord, potentially damaging the USB port it is plugged into. Using an add-on panel for controllers protects your motherboard and case, limiting any damage or wear and tear to the inexpensive, easily replaced panel.
Note that your motherboard may not have enough USB headers to support both the add-in panel and your case's built-in front USB ports. In that case, you can add a PCI-Express controller card that has an internal header. Just make sure the card and the bay or case use the same kind of connection. Some use motherboard header connections, others a regular USB A to B cable. An example USB bay panel and controller card are linked to below.
A wireless keyboard is recommended for gaming whilst sitting on a couch in front of a TV. This is to reduce cable management and to create a cleaner clutter-free look. Wireless keyboards come in a number of varieties, including Bluetooth and 2.4GHz wireless. 2.4GHz tends to be simpler to use, but has poorer signal range and requires the use of a USB dongle. Bluetooth is more reliable, has a higher range, and many systems have it built in.
It is recommended to keep the Bluetooth or 2.4GHz dongle within line of sight of the wireless keyboard or mouse to reduce potential input lag.
Another solution is to use remote keyboard and mouse software that can be controlled with a smartphone.
While it's possible to use a keyboard on one's lap or on a coffee table, it's possible to get into a very comfortable position by using a specially designed desk. Usually adjustable laptop desks do a good job.
Many PC games have built-in controller support, especially recent releases. PC games can be played with a wide variety of controllers, even those from other systems (e.g. the PlayStation 3 DualShock 3 Controller), but the Xbox 360 Controller is the most widely supported. It is also possible to add controller support to games that do not have it. See the Controller page for more information.
Modern LCD TVs work much like LCD monitors but have additional features such as auto-contrast and 120Hz motion. This looks fantastic on the shop floor but it can add between 50-200ms of input lag. This level of input lag makes gaming on the TV sluggish and unacceptable.
Most TVs do not add video processing through their DVI and VGA inputs. If using HDMI, most TVs allow a 'Game Mode' option which one will want to switch on which eliminates the processing. It is also very likely that one will want to find any 'sharpness' or 'fineness' settings and turn them to 0 so that high resolution text can be easily read. In the operating system settings, one will want to make sure that ClearType is switched on and web browsing is legible. Windows 7 also has excellent interface scaling options which one may want to turn on to 125% or 150%.
If considering a new TV purchase with gaming in mind, it is best to try to find a model with little input lag. Paradoxically, many of the best TVs for PC gaming are also the cheapest and best value for money. It seems that added features of TVs slow down the processing of images.
Unfortunately, not all TVs using HDMI inputs accept full colour information. Saturated colour text (red on black background) will appear jagged and possibly unreadable at smaller font sizes. Since the vast majority of HDTV owners will only be watching TV or movies, this normally is of little concern to the manufacturer. This AVSForum thread goes into detail about chroma subsampling and has a small guide of TVs which exhibit this behaviour. Additionally, at HardOCP there is a forum post with a smaller subset of information about chroma subsampling and input lag.
Steam now includes a Big Picture Mode that provides a graphic user interface (GUI) specifically designed for HDTVs and allows Steam to be navigated using just a controller.