The MSX computer was born in the early 80s, around the same time that the NES was released. Yes, the Console vs. PC Gaming war has been around for quite a while. Many well known games were released on the MSX before other consoles, such as Metal Gear and Bomberman, although other games could be found here as well, like Contra 2, Dragon Quest and Gradius. Its graphics were great at the time, but fell behind the NES when it was released. There was a later model of the MSX called the MSX 2 which took care of that.

By far the best MSX emulator is openMSX, which is still in development today. As you could probably gather from the name, it's completely open source and their team is always looking for new developers.

Like many emulators, openMSX is completely command line based, but you can grab their GUI subproject Catapult. Since openMSX does not support a huge range of customization like other emulators may, the command-line is probably the easiest method. I have found Catapult to be a finicky application in the past.

openMSX touts their emulator as being one that aims for perfection, and its no doubt been on the right path for a while. Its support is incredible, as you can see on their features page. Opening a game is as simple as openmsx carta path, so it really could not be easier to use.