It's been three years since the eighth generation of #Video Game consoles began. The leading platforms seem to be the PlayStation 4 and the Xbox One. Each platform has a specific title that they're pushing in order to be the "must own" platform. Such titles are known as "Killer Apps."

Killer Apps are the software or program that compels consumers to buy the new hardware. They can make or break a console. This is a list of killer apps that have stood the test of time and are still just as fun to play today as they were back then. To be on this list, the game had to be used to promote a particular console or service and stand the test of time.

#5 Sonic the Hedgehog

To compete with the likes of the Super Nintendo and Mario, Sega needed a face for their console with a game that players wouldn't be able to put down. While partially responsible for provoking countless knockoffs and wannabe mascot driven games, Even though the Super Nintendo sported superior graphics and sound quality, Sonic was able to do what many had failed to do in his place and give the Big N a run for their money. Word of advice, though steer clear of the Game Boy Advance and Xbox 360 games that share the same name.

#4 Metal Gear Solid

Metal Gear Solid did what every killer app is supposed to do. It showed off the hardware of the console, made players want to buy a PlayStation, and left a huge impression on everyone who played it. Not only did it elevate the Metal Gear formula, it also revolutionized English translations in video games; sporting the finest English voice acting and revised dialogue for a Japanese developed game at the time.

Where the characters and dialogue in localized games such as Resident Evil sounded stiff and unnatural, Metal Gear Solid's were anything but. Metal Gear Solid does show its age in certain aspects: character models look blocky, the animations are dated, and some of the lines are a bit cheesy. Regardless, it helped establish the PlayStation as the definitive console of the 32-bit era and it's still just as fun to play today as it was in 1998.

#3 Super Mario Bros

Super Mario Bros was one of the first games to feature an environment that scrolled as you moved. It introduced the concept of distinct looking levels. It also served as a blueprint for the platformer genre and the many games to follow in its footsteps.

Super Mario Bros showed that the video game industry could be profitable and adapt to accommodate consumer taste. Most importantly, it's fun. It controls great, it's easy to pick up and play, and it flows magnificently.

#2 Half-Life 2

Half Life 2 was a game that was truly ahead of its time. It boasted the most expressive and detailed character models of the time, clever and fun weapons, and some of the unique storytelling and characters that this industry has ever seen. While some of the physics puzzles and NPC models are showing their age, there are aspects of this game that have yet to be surpassed by most first-person shooters today.

 It was the first game to use Steam: a distribution service that is still used by Valve and gamers to this day. As of now, Steam has yet to be topped by any other distribution service and Half Life 2 is still regarded as one of the finest first-person shooters of all time.

#1 Tetris

Tetris was the first form of recreational software to be exported from the USSR to the USA. Nintendo distributed it and used it to promote the Game Boy. The platform helped make Tetris a financial success and cultural phenomenon. While it may not have had cutting edge graphics or an epic storyline, Tetris had a solid core concept executed absolutely perfectly. Those blocks falling down and turning around are still just as aesthetically pleasing and responsive now as they were back in the day.