None of those are really pure shooters. Let's see shooter with RPG elements, FPS with spy stuff, don't know, tactical squad-based shooter, same, shooter with RPG elements. Second row: RPG with shooter elements x2. Pure shooters are for example Doom 3, Call of Duty, Serious Sam, Farcry, FEAR, Quake.
Maybe you just don't like plain shooters where you just shoot stuff? Even Half-Life keels a bit to the puzzle side. Half-Life's biggest plus is that it never does the same thing until it gets boring. The experience is very directed and varied, you never just run through corridor after corridor mowing down enemies, there's always some kind of twist to it. The shooting part isn't even that good compared to newer shooters.
I'd recommend it, HL1 does the scare thing way more than 2. As I said, HL2 keeps mixing it up, one moment you're escaping from Combine soldiers, the next your in sewer tunnels with some zombies then a helicopter is chasing you. It's a fun experience, even if you don't like FPSs all that much.