Master of Magic
Platform: Anything that supports DOSBox, originally PC
Genre: 4X before it was called 4X
Released in 1994, Master of Magic is now old enough to drink. And despite being a game well worth playing, it shows its age. People who weren't fans back in the day may not be able to get past the antique graphics or the clunky UI, but if you can the game beneath is something amazingly good that still hasn't been really successfully duplicated. If you like 4X games you owe it to yourself to try Master of Magic, it's cheap through GOG. There is also a Master of Magic remake, of course, and I'll be reviewing it later, but I recommend the original for the 4X fan who hasn't tried it yet.
Master of Magic was released shortly after Master of Orion,  and was intended as a sort of companion or counterpoint to Master of Orion. Like Master of Orion, Master of Magic features a blend of strategy and tactics, the main action takes place on the world map but when combat begins the player is given a tactical map and interface to direct individual units.
It wasn't originally well received, it was buggy and the AI was broken on release, but that was patched and the game became enshrined in the hearts of 4X fans. So don't let anyone tell you that releasing a broken game and then patching it post release is all that new, they were doing it back in 1994 too.
Master of Magic is a somewhat odd beast, and my grade of A- may well be tainted by nostalgia but I don't think so, it really is an amazing game. An amazing game that had many problems baked right into the core mechanics, things that were lamented at release, but in retrospect turn out to be why, 21 years after release, people like me are still playing it from time to time.
To classify the problematic, yet in a weird way good, aspects of Master of Magic I'd say that they make a sort of accidental form of asymmetric game play. The simple fact is that Master of Magic is not balanced. At all. If you start as a human you get access to the full tech tree and the paladin special unit which is immune to magic and can curbstomp pretty much any other unit in the game. If you start as a lizardman you get a tech tree that's more of a tech shrub and your units can swim.
Yet, despite that, you can win playing nothing but lizardmen. It requires a completely different play style than winning playing with humans, or high elves, or orcs, or any of the other "better" races, but it is possible.
Magic is similarly unbalanced. Magic is broken into color based schools, green for life, white for healing, red for destruction, black for evil, blue for air and metamagic, and some are simply better than the others. It is undeniable that the magic in Master of Magic is as unbalanced as the races. Start with blue magic and you can summon Phantom Warriors, who mow through most early game units easily, and by late game summon Sky Drakes and throw lightning bolts with enough power to one shot just about any unit. Start with white magic and you might as well not bother casting spells until mid to late game, and even then your spells will suck compared to blue or red, or even black or green, spells.
And yet that very lack of balance is why I keep playing. Never mind that Master of Magic helped define the 4X game, never mind that it was a truly innovative break from Civilization and Master of Orion. The fact is that the lack of balance made the game fun and challenging in a way that even modern AI (which often isn't really that much better than antique game AI) or multiplayer often lacks.
Because you CAN win playing a wizard with all white magic and nothing but lizardmen. You've got to take a human wave approach to combat and expansion, you've got to use your magic to maximize population and healing, you have to hit your enemies fast and hard before they can start pumping out units that will smash your armies solo, it's risky and you may lose horribly, but it can be done. And succeeding with all the odds against you feels damn good.
There are a handful of deliberately asymmetric games out there, AI War is the canonical example but Sorcerer King represents an attempt to intentionally achieve what Master of Magic did (I think) purely accidentally. Asymmetric games are hard to design because the whole point of them is that they're unfair, and making something unfair fun, winnable, and challenging is difficult to say the least. That Master of Magic succeeded in doing it basically by accident is amazing.
One of the ways Master of Magic succeeds is with a game that had a sandbox feel before the term sandbox had been invented. They developed a game with a greater variety of units, a huge number of spells and magic effects, and allowed the players to mix and match as they chose. The ability to customize your wizard allows you to minmax traits and spellbooks to create an unstoppable force of nature who can stomp through the game even on impossible difficulty with no real trouble. Or you can go the opposite route and make a wizard who has a mix of traits and spells you think simply can't win, and then win anyway.
And, unlike in some games featuring magic, the magic in Master of Magic can truly shake the world. At high levels you can not merely rise individual volcanoes, you can cast a spell that will automatically rise several volcanoes every turn (except in your cities of course) and eventually reshape the whole world into a hellscape of lava flows. You can cast spells that plunge the world into eternal night, or slowly corrupt every bit of terrain making it unlivable. You can cast spells to raise every fallen soldier as a zombie in your rotting undead army, or stop time for everyone but you so you can smash them piecemeal and steal their resources in the blink of an eye. Every one of those spells is horribly unbalanced, and fun in a way that the carefully balanced play of most games simply can't match.
Master of Magic is a game that no major studio would dare release today. But it's good, and you should try it.
 Nostalgia is always profitable so naturally Master of Orion is being rebooted. Here's the Steam page.