Since you didn't mention anything about a price range, I'll just give some general advice.
OS X (the operating system on Apple computers) has some pretty good video editing software. That's not to say that there isn't good software on Windows, but in general people seem to prefer Macs for video editing.
The trade off is that you pay considerably more for Apple computers. This extra doesn't buy you much. The parts in an Apple computer are no better than the parts in a Windows computer. They aren't any faster or newer, they aren't any less prone to failure and they certainly aren't Apple exclusive (in fact Apple usually lags behind several months on hardware adoption). This extra cost is commonly referred to as the "Apple tax" and it applies to almost all of their products.
Also, video game support on Macs is, in general, pretty bad. Until recently most game developers ignored Macs entirely due to their pitiful 8% market share compared to Windows' 90%. It's better than it used to be, but games are almost exclusively developed for Windows, then ported to Mac. I've seen games where support for Mac was much worse than for Windows as well, due to the producers focusing on the much larger Windows user base.
Still, if you really want a Mac and can afford to pay the extra for it, Final Cut Pro X is an easy to use piece of software, though it's been dumbed down considerably to cater to the average Joe. Used to be the standard for professional editing, but its users left in droves when features critical to professional workflows were removed in the latest version.