Sid Meier's Civilization V

 Civilization V is an epic strategy experience that follows a lineage of games that hang delicately balanced between deep, hardcore gameplay and accessibility.  Somehow, though, Civ 5 continues to refine and improve upon Civ 4, a game that I thought was probably as good as these games could get.  Many improvements and additions make Civ 5 the most well thought out and well polished turn based strategy I think I've ever played, and that same "Just one more turn" feeling is back in full force to keep Civ 5 as addictive as just about anything else you can experience.

Many of the changes in Civ 5 don't change the core of the gameplay - you still build cities and improve them with various buildings.  You still march through a tech tree to unlock new buildings, resources, tile improvements, and military units, and many of the same victories are available: by launching a spaceship, military conquest, cultural superiority, or even by diplomacy.  One great thing about Civ 5 is that some of these victory options are a bit more balanced than they were in Civ 4, where the spaceship was the "standard" victory that was generally easier and more intuitive than the others.  Launching a spaceship is still somewhat of the standard, but a re-working of the culture system and tweaks to how warfare is played make those options much more attractive.

The most immediately obvious difference in Civ 5 is that it is now played on a hexagonal grid, rather than a grid of squares.  This is part of what makes military combat more fun, because it allows for a bit more maneuvering of units.  The move to hexes is a big plus for the overall gameplay, and thinking about playing Civ in squares now just makes me cringe.  Yet another big difference that works really well is the addition of City States, which are small, less powerful civilizations that only ever consist of a single city.  There are many ways of interacting with them, and all options can be beneficial.  They add another level of thought to how you run your empire without really detracting from the bigger picture, which is great.

Another big part of all Civilization games is the roster of leaders and their various bonuses.  While Civ 5 has a diverse cast of leaders with unique abilities, they don't really feel very balanced.  Some Civilizations have bonuses that are only helpful during certain time frames (usually early on in a game), while others have bonuses that are not only always helpful, but are sometimes more powerful as well.  Also, the AI sometimes acts in strange ways, and it can be annoying when you've beaten a civilization back to their last stand, and want to call a truce rather than invest in enough military to finish them off, but they still won't negotiate peace without you giving them everything you own.  These types of situations aren't common, but it can be aggravating when they happen.

Overall, this is a massive game that is very well implemented in almost every area - and the foundation is so good that the few problems don't really even matter most of the time.  By being both deep and accessible, Civilization 5 is a game that any strategy fan should consider, and I bet that if you do, you'll be saying "Just one more turn" with the rest of us before you realize it.