Well, you folks seem to be eating the old school stuff alive! I like that! Here's another classic . X-Com Ufo Defense. This is an insanely detailed, yet very easy to play strategy game from way back in the day centered around the invasion of Earth from an alien covenant (and not the halo kind). The game takes place in two different views, one of which being the "Geoscape" which is a real-time, 3-d rendering of the earth where you build and manage bases, intercept ufo's you've detected with your sensors, and send landing parties to go scout things out once you've shot one down or found an alien base.
This is where the fun begins. The second view is a semi-omniscient view of your squad and landing craft. It is played slightly like a turn based RTS game. You can only see the terrain that your soldiers can see though, fog of war? Naa, no thanks! Simple blackness will keep you guessing as to where the aliens are gonna snipe you out from next.
Once you manage to either lose your whole squad or wipe out all the aliens, you can go back to base with all the new alien gear you found and start using the research facilities you bought back in "Geoscape" mode to figure out what makes those aliens tick, and how their guns work! Next thing you know, you're manufacturing alien technology at home, and using it against those greys!
I could go on for hours about this game (as i'm sure you're figuring out by now) This is one that kept me playing till 6 a.m. back in the day when the original Baldur's Gate was the new hotness. However, I'll let you try this one on your own.
Bonus! This package includes multiple "copies" of the game, each optimized for different operating systems. This has been tested on everything up to Vista, and works with only minor graphical glitches. Worst case, a guy i know on Vista had a 1 inch black bar on bottom of screen which did not "overwrite" play space, it just made the "render able" area smaller, so no content is missed behind the black bar, but he didn't care, cause he couldn't even believe it worked on vista! Anyway, for s's and g's, Mode 2 works best for me, and it seems everyone on vista too, you'll see. Enjoy!!!