I have to add another game to my previous submission...
Sniper: Art of Victory
Within the genre of FPS games, TCS (Tactical Combat Simulation) games are my personal favourite sub-genre, with games like the first few generations of Tom Clancy Rainbow Six and Ghost Recon series titles, and the ArmA series being among some of my favourites. I also am fond of games which aren't strictly within the confines of the sub-genre as well though, like the Sniper Elite series, and the Sniper Ghost Warrior series.
Sniper: Art of Victory is the first game in the Ghost Warrior series or perhaps more accurately it's predecessor, and while the game is rather dated now, and pales in comparison to all of the other titles I've mentioned above both in story, dialogue, realism and complexity, it still seems to be a fun game to me so far (I'm only a few missions in currently so this opinion could change). It's probably the weakest game in all the ones I listed above, but it is still enjoyable at least to me - despite the fact it has only a 31% "Mostly Negative" rating on Steam.
It seems like the type of game I'll want to complete and then move on to something else, rather than being one which is likely to have any major replay value. A short diversion through the backlog as it were.
Sure, the game has some AI flaws, movement flaws (I'm perpetually falling off ladders), and other quirks, but it's not as terrible a game to me than it would seem the majority of people seem to think about it. From what I've seen so far about the game I'd give it a 65% rating on the surface, but then have to lower it down to 60% due to lack of ability to change the game resolution, lack of widescreen support, and lack of ability to make the game show up on my secondary display instead of the primary display.
Despite the inherent flaws it has, I'm still enjoying it enough to keep playing it even though I know I have better games in the genre which I haven't played all the way through yet. But then again, I'm a sucker for sniper type gemes and there aren't enough of them out there. :)