Game recording software. I see a lot of misinformation...
OK, so I see a lot of talk about these cpu-based screen recorders and other software, but these really hog resources and slow your computer to a huge degree. These are older technologies that work with all computers... but they are slow. GPU-accelerated options are much faster, if you have a compatible system.
There are many options out there, and many are good for many situations, but check these two out FIRST, before you go spending money on FRAPS and the like.
These are both FREE and made by AMD (ATI) and Intel (nVidia) respectively. They are GPU-accelerated, so run on your card, and don't reduce system performance like the CPU-based options.
They are largely similar, and generally only work with relatively newer cards, but if you have a compatible card (jsut google it) then this is where to start.
for people with AMD (ATI) Cards: Raptr http://raptr.com/amd
... and for Intel (nVidia) cards: Shadowplay http://www.geforce.com/geforce-experience/shadowplay
I've used both, and I do prefer nVidia's Shadowplay. However, it has been around for quite a while longer, so I'm sure AMD will catch up. They have already fixed many of the most annoying bugs.
I haven't used FRAPS or other software for gaming in years. They aren't the best for everything, but for game recording you can't get any better without external hardware.