ditto on half-life 2. I felt extremely immersed the whole time I played.
dunno how you felt immersed
i blocked the combine guard on the turret in the drive part with a can and just went past
theres multiple moments where combine just rush in a line so all you do is shoot with the smg and all your hear is "Augh! *sstchhaaaa-ssssshhhzztt* 10-4-01 officer down" and "Ooogh! *SttchPLIPPlIpPlIpPllP*" so much that I memorized the sounds.
I got immersed in ravenholm,though, so much so that when I first played it I was scared to stuff of fast and poison zombies and still get the heebie jeebies when I see or hear a poison zombie.