If you want high definition quality on your monitor then you could buy those expensive transcoders like the VD~Z3 Enhanced, but then your monitor would need to support it. So it might be better to get a capture card, and plus, you can record the video as well.
I would stick to PCI capture cards as they have better transfer rates at 133M
B/s as opposed to USB2s 60M
B/s (480M
b/s), and you would also get lag with the USB which isnt ideal for playing a game.
Ive been searching around for good TV tuners for a while, and Ive narrowed it down to these two. They both offer significantly high picture quality, performance and features at a good price.
This
Hauppauge PVR has been a very popular choice for a long time, unlike the Pinnacle, it features hardware encoding which takes the strain off the CPU, so you can get high quality picture without losing the framerate. However the software is not as good as the Pinnacle but it does its job fine (personally I find it quite good). Plus it has a remote!
The
Pinnacle PCTV Pro is also a very good buy, especially as people say it has better picture quality than the Hauppauge, but it does not feature hardware encoding meaning that the CPU has to work at 100%, so you'll get more dropped frames as the quality goes up. On the other hand it comes with better software.