A way too long introduction to retro consoles, modern TVs and gameplay capture.
To capture game consoles you need a device that accepts the video and audio from your consoles. This chapter lists some of the popular options as of late 2014. If you need some help with choosing what device is right for you, you can check the guide for a list of important qualities.
You can also skip ahead to the next chapter for the highest quality capture devices.
The cheapest devices you can get are USB grabbers. These small dongles usually have inputs for composite and S-Video along with audio. Composite should be avoided at all costs, as it just can't deliver a picture quality that people would want to watch. S-Video on the other hand can deliver decent quality. As all devices that will be discussed, USB grabbers vary greatly in their quality. There are decent devices like the EZCap and Dazzle, but also a ton of really bad clones that don't even support 60Hz from PAL consoles. If you absolutely want one of these I would highly recommend the IO Data GV-USB2. These devices are limited to 240p and 480i. In most cases they do not distinguish between 480i and 240p and record everything as 480i, requiring manual deinterlacing to get good picture quality.
This is a big category. These range from devices that only support component to devices that will deliver lossless 1080p capture at 60fps. Some highlights of this category are:
Elgato Game Capture HD
One of the first capture devices that could record in 1080p. It offers a digitial HDMI input along with analogue inputs for retro consoles and component sources. It features an onboard H264 encoder that removes the stress from your CPU and delivers small file sizes with still great picture quality. It also has an HDMI passthrough feature that allows you to play the games on your TV while they are recorded on your PC or laptop. The downsides are that 1080p content is only recorded at 30fps and that the PC application has a few seconds delay, which you will have to account for if you want to use it for live streaming.
Elgato Game Capture HD60
The successor to the Elgato HD. Unlike the previous version, this one supports 1080p at 60fps. In the upgrade process it lost the analogue input, so it only supports HDMI. It still works on USB 2.0 and has an onboard encoder.
A high quality external capture device with HDMI and analogue inputs and passthrough outputs. It can record 1080p lossless at 60fps and it can also record retro consoles correctly.
AverMedia ExtremeCap U3
A USB 3.0 capture device without an onboard encoder. In theory you get basically lossless picture quality in 1080p at 60fps. The biggest problem with this device is that it highly depends on the USB 3.0 chipset of your PC. You need specific verified USB 3.0 chips to use its full potential.
AverMedia Live Gamer Portable Lite
An alternative to the Elgato HD. If you want a device to record your HDMI consoles then this is a cheap option. It only supports HDMI and 1080p is recorded at 30fps like on the Elgato HD, but for many people this will be enough.
Besides external devices there are a wide range of intenal capture cards that use the PCIe slots of your PC.
AverMedia DarkCrystal HD Capture Pro
Also known as H727 or C027. This is a cheap internal card that allows you to losslessly capture 720p from HDMI. It also offers component, composite and S-Video inputs. The H727 became famous because an old driver version lets you record HDCP protected video. The HDMI input only accepts limited range RGB and the analogue inputs only deliver average quality. AverMedia recently revised the card and lowered the component quality significantly in the process. Still, it's a decent card if you want to record 720p from HD consoles and some retro games and don't want to spend more than necessary.
Note: I got feedback saying that the card supports full range RGB. I have checked it with my card again and mine does not record full range RGB correctly. Apparently the newer H727E version of this card supports full range RGB.
Micomsoft SC-500N1 / Startech PEXHDCAP
One of the most interesting capture cards that was released by Micomsoft in Japan and later brought to the west under the Startech brand. This card is limited to 720p / 1080p30 on its HDMI input, but unlike the C027 it handles full range content correctly. Besides the HDMI input there is a component input that delivers excellent quality beyond any other device I've seen including high end scalers and TVs. What makes this card so special is that it has a DVI input that accepts analogue RGB signals. It actually accepts 15kHz RGB from a wide range of devices. This card will give you excellent quality from any home console that can output RGB, as well as most arcade boards. There are some arcade boards that are cut off at the sides, but this usually only happens for boards that are very far off from the 59.94Hz standard. The only problem with this card is that the driver disables the C1 sleep state of your CPU which results in higher energy use and more heat output.
Update: On Windows 8 this problem seems to be fixed with the latest drivers.
The successor to the SC-500N1. This card supports lossless 1080p 60fps capture and adds high quality composite and S-Video capture to the mix. It also comes with a passthrough which is highly appreciated. Other than that it has the same perks and problems as the previous card.
Recording PC gameplay is easier than recording consoles, as PCs offer an array of capture programs. Of course you can also use any of the HDMI capture devices.
The most popular capture software in the past was Fraps. Fraps allows you to capture gameplay from most games and save it to your harddrive. The captured videos are nearly lossless and can become huge very quickly. Capturing videos in intense 3D games will have a noticeable hit on the game's performance, so you need a beefy system. If your system is fast enough you can also record at higher refresh rates like 120fps or higher resolutions like 2560x1440. It is recommended to save the videos to a seperate harddrive that doesn't have to load the game at the same time. A RAID array of multiple disks might also be required to handle the high write requirements. Recently there appeared more options besides Fraps. Dxtory is like Fraps a paid program that can record your gameplay, but unlike Fraps it offers a lot of settings. One of the most interesting settings allows you to record with any VFW encoder like Lagarith or x264. Especially x264 can compress your videos very well without a huge hit on the quality. To use it you will need a strong CPU however. There is also the free MSI Afterburner which can not only monitor your GPU but also record gameplay.
Like consoles you can capture PC gameplay with a capture device. This can be especially useful for live streamers who can use one PC to run the game and a second PC to stream the gameplay to services like Twitch.tv. It can also be used to record on one PC and offload the encoding to the external device. Before you get a HDMI capture device you should think about the audio part. When you use an external capture device you have to send the audio through HDMI as well.
If you have a recent GPU you can also record gameplay with the onboard H264 encoder of your graphics card. For NVidia users this can be done easily with ShadowPlay through the official NVidia software. AMD users can use Dxtory or MSI Afterburner together with the AMD VCE h264 encoder (OpenEncodeVFW).
If you want to capture retro consoles and you are more concerned about the cost of the capture equipment than the quality of the footage you can record, then there are lots of cheap options. A device like the IO Data GV-USB2 or even an EZcap will give you good quality for any SD console that is limited to 240p and 480i. In this case you should still use S-Video and avoid composite. Check out this tutorial by TheThrillness for a step by step instruction on how to use these devices.
For consoles that can output games in progressive 480p mode you can still use an S-Video device, but you will get better quality with a component capture device. These devices are a bit more expensive, but there are lots of options out there. Some require a PC, others will work on a Laptop with USB and there are even a few devices that do not require a computer to record gameplay at all. If you want to capture HD consoles on a budget you should aim for a HDMI capture device that can capture 720p. As with the component capture devices there are a lot of options and often they offer both component and HDMI.
The following chapters will focus on some of the best options for high quality RGB captures.