Street Fighter is, as you likely managed to figure out from entry #19 on this list, a series I've enjoyed for many a year. I already explained the backstory of the SF games in the previous entry, so I'll talk a little more in-depth about SFII this time. The first Street Fighter game I ever played was Super Street Fighter II: The New Challengers. This game introduced the world to Cammy, T. Hawk, Dee Jay and Fei Long, bringing the character roster to 16. Everything about this game was perfect. Despite there being 16 characters, four of whom were playable boss characters, the game somehow managed to be perfectly balanced.
For instance, Ryu and Ken are basically middle-of-the-road average dudes. They even have the same moves. They each have one of those moves that causes more damage than the other character does, and their Tatsumaki Senpukyaku (Hurricane Kick) has a slightly different effect. Other than these differences between the two of them, they're basically completely average in terms of speed, strength and special abilities. Zangief is the strongest character in the game, but he's incredibly slow and his moves require him to move in close to an opponent to get them, allowing a more nimble fighter to attack him. Vega is the fastest character in the game, but his defense is also the lowest in the game. The two ladies, Chun-Li and Cammy, both fall into the category of "fast but weak" women in games. Each of the characters have this kind of balance that means no one character is necessarily better than another and, in the hands of equally competent players, any battle could go in either direction.
The final true revision of SFII was Super Street Fighter II Turbo. This game added the Super Combo moves, which are now standard features in Street Fighter games, added the ability to juggle an opponent in the air with extra attacks (almost certainly influenced by Mortal Kombat allowing players to do this when previous revisions of SFII had no such feature; as simplistic as it sounds, it was considered a major feature at the time and it's practically an industry standard these days), included four different speed settings (hence the Turbo part of the name) and introdced the character of Akuma. That's a story that bears further discussion but I don't want to get too sidetracked for now. Suffice to say, SSFIIT was and still is an incredible game with so much replay value.
Hyper Street Fighter II is basically the "ultimate" edition of the game. It was released in Japanese and Southeast Asian arcades in 2003 as an anniversary edition of the game. What makes HSFII stand out is that it basically lets you pick not just any of the 17 available characters, it lets you pick what version of them you want to play as. What that basically means is you can play the most updated version of that character from Turbo, or you can play any of the earlier versions of that character from previous revisions of the game, right back to their "normal" self. This is, of course, restricted in that characters may only go back as far as the game they first appeared in. What this means is that some moves are stronger than others in different versions, some characters move faster or slower in previous revisions, even some of their alternate colour palettes are only found in certain versions.
When HSFII made its way to home consoles, it was made even better in that you could now also select the kind of music you listened to during the fights, from the original music all the way up to brand new remixed tunes. The SFII soundtrack is one of gaming's absolute finest and to hear all these classic songs remixed is a thrill (as Capcom used to great effect when they got several members of the OverClocked ReMix community to create the soundtrack to Super Street Fighter II Turbo HD Remix). On top of this, the home console editions feature (a sadly edited version of) Street Fighter: The Animated Movie, which is easily the finest Street Fighter feature yet made.
If you want a competitive, addictive, easy-to-play, tough-to-master fighting game, Hyper Street Fighter II may very well stand at the top of the pile.