Steam is a sort of online storage account for playing multiplayer games. Some other uses for it are to avoid having to keep physical backups of games, since you can download the games on your account at any time or place. The copyright protection is in the security of your account, thus no third party package that checks for cds or cd keys or so forth. Login to your account using the normal user name and password routine and you have access.
I mention this sale because a lot of old games are going for under 10 dollars. And some recently old games are going for less than 5 dollars. King’s Bounty the Legend is worth a mention. It’s got the RPG mechanics of Warcraft III with a much more detailed world and quest offering, built around a Warrior-Paladin-Mage skill tree reminiscent of Dark Messiah of Might and Magic (FPS-RPG). The tactical gameplay is situated around a Might and Magic 5v5 tabletop setting that is turn based. The difference is subtle, though, and I think it is a rather innovative improvement. There is a lot of character to the specific unit designs and much of it is surrounded by quests which unlock specific units. Rather than simply conquering territory and opening up undead units, there’s actually a pretty good atmosphere and context behind both the specific place where you get it and how you get it. And these include animal units, dwarves, plants even, etc.
Indigo Prophecy is also a game I played awhile ago. Designed for the console controller, it has a sort of repeat the pattern-color theme that allows you to have direct control over the story line. The story line is half cinematographic inter-active novel and half crime-mystery. It was an invigorating experience and really put you into the story. The interactivity is simple, all you have to do is to press 4 directional arrows in the right order and in the right color. This can seem boring at first, but it allows you to focus on the story and dialogue. In action scenes, however, this ramps up and becomes moderately difficult, even for the quick of eye and hand.
The XCOM series is there. As well as some other oddities. Take a look and put in some of your favorite games as search terms.