BI:TAW, apart from the usual micromanagement introduces an unusual twist to the TBS games: always timed turns. While the amount of time given is usually enough to do everything (unless you're moving massive armies of over 50 units and doing it by hand), the fact remains that you cannot switch the timer off. This game also involves actually important weather and daytime, as well as intriguing plot that can be played from both sides. It is also one of the better looking games on this list.
#9: Stars! (PC)
Ah, Stars. The game that initially looks more like an Excel spinoff is actually truly complex and one of the most compelling 4X (that's eXplore, eXploit, eXpand, eXterminate) games in existence. There's plenty to do, loads of techs to invent, multiple approaches to try, an advanced race customizer, a giant galaxy and a whole load of players to defeat. Unfortunately, there's no hotseat mode and the AI players aren't the brightest...
Out of the great fantasy trio (Disciples, AoW, HoMM), this game has the darkest and most mature setting and lowest-scale battles (6 on 6 unit combat and up to four players in one scenario). D2 greatly improves upon the original, especially in graphics departament... The key feature of the series is a compelling campgain for each race, terrain claiming, and a unique unit system: in short, your units "evolve" when gaining an experience level, and their development is governed by improvements to your capital.
Test of Time is actually a standalone expansion to CivII. It adds fantasy and sci-fi settings, which involve playing on several different maps at once and a completely new technology tree, redesigned interface and a very good soundtrack in CD-Audio. Besides, it's Civilization!
GalCiv is an example of how a budget game can turn into a successful franchise. Some of you might have heard about this game - regarding the Starforce "controversy". Nevertheless, it's a great piece of 4X (and an awesome ship designer), which can be shortly described as Master of Orion 2's younger brother with great AI. Oh yes, designing new ships is lots of fun (not only this statement's redundant, it is also redundant).
JA2. Squad-level tactics, completely nonlinear camgain, good story, RPG elements, isometric graphics with good animation, and the most memorable collection of characters in a TBS. Also, where else you can use your trusty FN-FAL or Dragunov with a scope to rip 'em a new one?
AoW takes a lot from Master of Magic and Civilization (cities, magic spheres and research...), mixing it with godly music, well-drawn hand-made graphics, two nonlinear campgains, complex interracial relations and massive scenarios: up to twelve players with battles of seven eight-unit armies. Also, there is an unique, "Simultaneous" turn mode option where every player moves at the same time, which is very helpful in multiplayer.
Shadow Magic, a standalone expansion to AoW2, is really the pinnacle of the series as far as the multiplayer goes. An advanced random map generator, many races, more spells to research, improved diplomacy and a lot of minor gameplay improvements make this little gem really playable.
X-COM is quite possibly the first game to combine two levels of strategy: global, where you build, recruit, buy and research in "real" time, and squad, where you and your trusty soldiers go and blast aliens (or get their butts fried) in turns. What more, the terrain is interactive (why crawl to the door under heavy fire when you can just blow the wall up?) and all researched technologies are placed in "Ufopaedia" for your reading pleasure.
HoMM3... Well-executed mechanics. Beautiful graphics that really don't age at all. Massive amounts of epic playability. All this make this game the best possible option when going multiplayer and have earned it huge amounts of faithful fans world-wide.