I'm the same way. Most of what I have are First Person Shooters.
I'm not really sure what Stalker would be classified as, but I agree. It can be slow.
Here are some straight forward FPS games I have on GOG that I enjoyed (not counting the ones you mentioned):
Doom & Doom II - The old games from the 1990s. I recommend the unofficial source port gzdoom to modernize the controls and support widescreen. Try out gzdoom with the demo of Doom first to see if you're ok with the older looking graphics. GZdoom may take several minutes of tweaking in the menus before it plays how you want.
Doom 3 BFG - slow paced shooter. The game is slow to start, but eventually the action becomes more consistent, but although not frequent.
Quake 1, 2, 3, & 4 (Quake 3 is a multiplayer game that uses bots instead of humans so you can play offline).
Fear 2
Unreal - classic shooter. Slower than games like Quake and Doom, but still has frantic moments. More action than Stalker though.
Unreal 2004 - Another multiplayer arena shooter with bots (like Quake 3). A good game for when you just want to run around and shoot without thinking. I only play with bots.
Painkiller - over the top, lots of shooting with ragdoll physics galore. Has an area based system like the newer Doom game (enter room, kill all enemies to open next door, proceed to next area). Boss battles can be incredibly dull and slow though.
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Far Cry 2 is probably too slow. There are long stretches without action and dying can sometimes mess up your progress a lot.
Timeshift and Singularity are also pretty good (some light time manipulation mechanics in both), but wait to get them on sale.
Post edited December 19, 2017 by hudfreegamer