I'd popped on to see what might be in the pipeline and wing in a few suggestions of my own, but three of my biggest suggestions have already shown up - and a reminder of a fifth I hadn't expected, but I guess this would be the place for it.
So, these are going to be more "I second that opinion!"s than "try this game!"s. Not being a game designer, programmer, or even more than an overcautious modder, I can't offer a huge amount of insight into the back end of the game, but I found these interesting. Make of these what you will.
First.. uh... Seconding: Call of C'thulhu: Dark Corners of the Earth. A tense, tough stealth adventure game set in H. P. Lovecraft's most famous fictional universe, but with controls that make it play like a first-person shooter. It has some huge bugs that can make it almost unplayable (or in one instance, absolutely unwinnable) but probably nails the weird, hostile little town vibe Lovecraft seemed to love writing about better than any other game I've seen.
Second "me too!": Ares. A top-down space RTS with no voice acting, and I remember nothing about the music, but it has a dozen factions that all play wildly differently as you lead a galactic crusade to liberate Earth. The writing and the science-fiction world building they did for the game make it notable, at least, and they had decent two-dimensional Newtonian physics for the time. One interesting part of the plot, to me, was that you only left Earth at all because someone screwed up translating the message in a "Wow!" first-contact signal.
Third "try this game!": The UFO: After[blank] series. Three games - Aftermath, Aftershock, and Afterlight - that chronicle humanity's struggle against invading aliens. Having played Shock and Light, I can see how they get compared to X-Com a lot: you have a strategic resource and research management overworld game, a fairly brutal top-down squad-based tactical game, an almost endless amounts of customization, but it isn't turn-based. They managed to find one of the rare ways to make a squad-management game playable without forcing turns or leaving ally controls in the dubious hands of the computer.
The minor "try/remember this game!" entry was Hocus Pocus, a shareware side-scrolling action platformer from the mid-90's with DOS graphics and a Pratchett-like feel to the writing. You have to wipe out a bunch of interdimensional squatters charging tolls along the magic paths between dimensions. As the manual puts it, "especially the path to the Beautiful Amazon Tribes Before the Time of Clothes era. This bothered the [wizard] Council, who wanted the obstructions "removed" so they could get on with their Amazon studies."
The first of the two remaining big "check this out" , and the first I haven't seen listed previously, and have been thinking about since the Test Drive 2 Game Dungeon: Chuck Yeager's Air Combat. An early 1990's flight sim with a fair* amount of realism, you fly selected German, American, and Russian fighters in historical missions from WW2 (the European theater, anyway), Korea, and Vietnam.
* "Fair" here means if you eject during career mode over friendly territory, you're probably fine, but bailing out over enemy territory means you might be captured, and get a game over. Also, exceeding your plane's maximum speed by too much can and will destroy the airframe. Probably not what Ross was thinking of when describing Test Drive 2's steering, since it isn't random, but a flight sim where your plane's wings fall off totally does exist.
Finally, there's Operation Neptune. It's a puzzle-type game with some arcade-like gameplay, where you guide a Deep Sea Research Submersible through dangerous trenches and around obstacles, collecting data modules from a crashed space mission that reveal the game's story. It's kind of unique (to me, anyway) in that it's an educational game: the puzzles are all math-based, and designed to be relevant to the situation. For example, to dock with an undersea base, you might have to solve a question about volume to counteract a minor flood, or about redistributing weight when you pick up a data module. It's aimed at (I think) a younger audience than most of the Game Dungeon, but definitely notable.
I dunno - while I have some details on these, what I've put here is all or most of it: what I remember of the game that isn't just rephrasing the wikipedia article, or finding new and exciting ways to say, "hey, yeah, I remember playing that game in middle school!". I think these games are worth a look, but what I have here is a bit light for six new threads.