Of course, there are a lot of strategy games available for you to enjoy, and a lot of good ones. But I'm going to focus on three games, or three series rather, and compare them against each other. Enjoy.
Starcraft 2 earned itself a lot of awards in 2010, and I daresay it deserved every single one. Often considered the "King of Strategy", Starcraft has become the highest selling strategy game on the market, not to mention a national sport in Korea.
Starcraft's success is in it's simplicity, and also it's complexity. That's a paradox if I've ever seen one, but it's true. The gameplay of Starcraft is centered around gathering resources, expanding, building an army, and engaging your opponent. Your goal is to destroy your enemy's army, and eventually, their base. The way to win is to keep your army large, while also making it stronger, by researching improvements, and unlocking more powerful units.
The thing about SC2 is that your enhancements do not carry over from one game to another. You begin every match with a clean slate. A base and 5 harvesters, and from that you create an army. The campaign is great fun, but really boils down to a series of missions, albeit with varied objectives. Multiplayer is where the legs of SC2 lie, and the key to it all is balance. Three races to choose from, each one with it's various units. Winning is about knowing how to best match your opponents army.
Gameplay is broken down into two parts: Marco and micro. Macro is, for all intents and purposes, the 'strategy'. Deciding how to make and spend your money, and building your army. Micro are the small-scale actions that take place when you engage your opponent in battle. Sieging tanks, burrowing Roaches, and all similar actions. This is also known as "tactics".
All in all, every game of SC2 is like it's own war, rather than a single battle. Rarely will a single engagement decide the match, and sometimes they can be drawn out over almost an hour, both players scrambling to control the map.
Though it earned almost equal praise as SC2, Civilization V was not played nearly as much. I'm not sure why, as it is truly an outstanding game. However, it is far different from Blizzard's goliath.
Unlike SC, Civ games are all about building your civilization up from a single town, discovering new sciences and technologies, and eventually, conquering the world. How you go about this however, is up to you. Of course, you can march through the continent, sacking every city in your way, but the real challenge is in forging alliances, and winning through respect, not fear.
Civ games are turn-based, with all actual fighting done by the AI. This will put some off, who will feel as though too much is taken out of their hands. But while Civ. games forgo the ability to control troops in battle, they make up for this by being perhaps the best "strategy" game out there. Mastering the economy, keeping cities happy, and researching new technology allows the player to more rapidly take over.
There is no real story to the single player, but it excels in giving the player absolute freedom of choice. A single campaign can easily eat up 20 hours. Multiplayer is more fast-paced, but the focus is the same. Multiplayer does not feel as fleshed-out as the SP, but it is great to test your strategic ability against live opponents.
For those who want to test their ability to lead a nation, from humble beginnings, to war, to domination, Civ 5 is the way to go. It may not give you the instant gratification of SC, but it makes up for that, and then some. However, there is one more game I want to bring up....
My personal favorite strategy series, seems to be left out of the conversation a lot when it comes to strategy games. The Total War series has been around since the first title, Shogun, was released in 1998. Since then, both Rome: TW, and Empire: TW have garnered much incredible universal praise from critics, and IGN listed Rome as the 4th best PC game of all time.
In my mind, Total War games really do offer the best of both worlds. The campaign is very similar to Civ. The player controls a country/empire, and leads it to conquer it's enemies. Both are turn-based, with emphasis on economy, trade, and growth. However, it is the actual warfare of TW that sets it apart.
Battles in TW are about as epic as they come. Remember I mentioned tactics when talking about SC, well that is the focus of the battles in TW. You have complete control over the units in your army, but whatever you enter with is all you have. If you realize that your army is ill-suited to deal with whatever your opponent has, than it is up to you to either outsmart them, or surrender. It may seem harsh, but no game really makes you feel like a general like TW does. Battles of up to 10,000 units are possible in Napoleon:TW (currently my favorite strategy game), and while controlling that many units is tough, the ability to do so is unparalleled in gaming.
I know people that never touch the campaign, and are perfectly content running custom battles with huge armies against the AI.
Online, players can wage campaigns against opponents, or perhaps do a quick battle with pre-decided armies (of equal strength). These are my favorite, and I've gotten quite good at them. If you ever play against me, be damn sure you keep your eye on my cavalry :).
I said Total War was my favorite. But as for which is best, that's really up to you. Though my comparison probably made SC2 sound like the weakest of the three, that is far from the truth. In truth, players who value skill above all will want to go with it, as no other game requires you to focus on so many different things at one time.
Strategy purists however, may lean towards Civilization. There may be no battlefield glory, but the huge range of choices and options makes it the gold standard for those with the heart of a leader.
And then there's Total War. Yes it's amazing as a strategy game, but at the end of the day, it's a series made for the arm-chair generals like myself.
Which is best for you? Only one person knows that.