When most mainstream games try to be "one size fits all", it's nice to have something that caters more towards your specific tastes, and works harder to satisfy a more specific audience.
List some game developers that serve your odd tastes in games.
Mine in no particular order:
Bohemia Interactive
Creators of the original Operation Flashpoint and the ArmA series of military sims. Sure they have some serious issues with their games being buggy out-of-the-box and needing numerous patches and fixes afterwards, but if you want a versatile and realistic modern soldier simulation for your home PC you'll be hard pressed to find better. They're also the makers of the Virtual Battlespace series of training simulations, used by the many military forces for soldier training.
Egosoft
Space sims have been a rather dead genre for some time but Egosoft has helped keep it alive with their X-series of sandbox-style space sims. They all have a steep learning curve, but in my opinion they're well worth the time and effort as they let you do just about everything you ever wanted to do in space, or at least sci-fi space.
Laminar Research
Developers of the X-Plane flight simulator. Since Microsoft closed down the studio responsible for their Flight Simulator series, X-Plane might soon be one of the few options left if you want a pure flight sim.
Introversion Software
The creators of unusual games Uplink, Darwinia, and Defcon: Everybody Dies. They continue to surprise me with their willingness to take big risks and try out unusual ideas. They're next project, Subversion, seems to involve things like "a procedural city generator" and "multi-part electrical and electronic systems using switches and logic gates". Sounds interesting.
(they better sure as heck not go bankrupt before finishing it!

)
Frictional Games
Creators of the Penumbra series of adventure horror games, which is probably one of the few recent games that managed to scare me. Their games aren't very long or high-tech, but have very immersive atmosphere, well thought out physics puzzles, and plenty of scares.
Quel Solaar
Quel Solaar is a one-man show consisting of a dyslexic guy named Eskil Steenberg making a rather unusual online game, Love, all by himself. He's also the developer of Loq Airou modelling program and helped develop the Verse network protocol for computer graphics software.
That by itself wouldn't be much to pay attention to, but the stuff this guy manages to pull off to make his game is nothing short of amazing. He does all his own coding, modelling, art assets, pretty much everything. He even makes his own development tools and makes them available for download on his site!
I remember a while back he claimed to have spent a couple weeks coding an automatic UV mapper to save himself from having to do any more UV mapping, and some people called this load of bullshit. His response was to make a trial of the tool available for download on his site for the "skeptics" to try for themselves!
Whether his game succeeds or fails, the work he has done to make it will have already helped to improve the efficiency of creating content for games.