In the last year or two, while (re)playing few games, I made some screenshots of different locations. There's both nostalgic and aesthetical value in it, for me at least, and these screenshots can serve if not as a motivation to pick up the title in question, then at least as a slice of what the game is artistically.
Most screenshots were made without HUD and they are typically 1920x1080, so they should work well as wallpapers. In Stalker, unfortunately, I didn't know how to turn the crosshair off for quite some time. Maybe I'll photoshop it away one day.
There's HL1 and Stalker as of now, I will add screenshots of several "Call of Duty: Black Ops" zombie maps later. There will be .zip archives with additional screenshots aswell.