For me who lost an entire decade of gaming (spent the 90s in the military. Neither time nor opportunity for that), X-Com was some legend. Last year, I finally bought it on Gamersgate and have it now. It works fine on Vista.
Now, I shall be viewed as an heretic but, despite the fine gameplay, I can't seem to play it. I only did a few years and a few missions. That's it: 90's UI and graphics repel me...
So I bought some newest clones: The UFO Trilogy.
UFO Aftermath doesn't work on my machine. Probably some bug.
UFO Aftershock was much fun: researching what happened, watch the story unfold, retro-engineering, squad managing with experience and weapons, combat missions with pausable real-time to give orders. There are for sure balancing issues but UI and game mechanisms are good, and the general theme appeals to me. Bloody aliens!! 
So I'll now try the third: UFO Afterlight (the one on Mars).
I got deterred by the bad reviews on UFO: Extraterrestrials. Is it really so near of the original game?
Steampunk + magic + aliens = mind blown.
Though I haven't read it yet, I heard some recent issue of "The League of Extraordinary Gentlemen" by Alan Moore is just about that: War of the Worlds with Victorian super-heroes. Might be worth reading.
Ah, I don't know why I write all that. I don't have those fond memories of yours on X-Com but I like that theme of life or death war against Aliens, with secret organisations, genocides and such.
As a TV-series, I loved [URL=http://en.wikipedia.org/wiki/Dark_Skies]Dark Skies[/URL]. Too bad it didn't last more than one season.
And the episode of Masters of Horror named "The Screwfly Solution", I found truly horrible.
So, keep the news coming and tell us about new implementations!