X-COM and its sequel Terror from the Deep are two veritable strategy masterpieces that need no introduction.

Massively popular and deservedly so, the only reason you find them here on this site (which is supposed to focus on underdogs) is that this is the by-now-hard-to-find native Windows 95 version, first released as part of X-COM Collector's Edition in 1998 :) For anyone who still needs convincing or has been living under the rock for years, you can find plenty of gushing reviews such as this one at GameSpot to change your mind:

"At first I didn't get it. The newsgroups were all abuzz about some game called X-something - everyone who played it seemed to become a near-zombie, talking about it incessantly and flooding the groups with endless threads and theories and strategies. Then, as a lowly intern at a gaming mag, I was given the game to take some screenshots for a review. It seemed interesting enough - building bases and killing aliens - but I still didn't get it. Frankly, it seemed tedious. I decided to take it home to see what all the buzz was about. Big mistake.

For the next few months, I spent every possible moment playing the game. Sleeping only a couple of hours a night, I would stay up 'till dawn playing, wake up minutes later and get right back into it. I was even going home from work at lunch to get a hurried hour in. It got so bad my roommates had a "talk" with me. Finally, I finished my first game, and proceeded to stumble about for weeks after, having paranoid delusions that aliens really were invading earth, cautiously looking for a flashing red "enemy in sight" warning in my peripheral vision.

And that was the brilliance of X-COM. The game managed to take two seemingly sterile genres - turn-based battle and resource management - and create a truly engrossing experience. The game is broken up into two main areas. As the commander of X-COM (a multi-national committee established to thwart an alien invasion), the player must construct facilities to house soldiers and research new technologies, while tracking alien movements and attacking their ships and troops. As more corpses and artifacts are recovered, scientists can be employed to learn more about the invasion and its origins. And every time the game starts to slow down a bit, a new piece of information will be delivered that creates a newfound sense of excitement and makes every battle seem that much more vital. Countless games later, the fun still hasn't diminished, and X-COM has held a proud position on my measly 400MB hard drive for almost two years.

If you call yourself a gamer but don't own X-COM, your collection has a more glaring gap than Ernest Borgnine's smile. Put simply, X-COM is a bona fide modern classic, standing proudly alongside Civilization and Populous as a benchmark in the evolution of strategy gaming."

Note: This download includes a fanmade patch that fixes the garbled graphics problem on Windows XP/ME/2000.