HL2 seems less hopeless, overall. I mean, as Gordon Freeman, you stand a big enough chance that the enemy actually respects and fears you.
And you get vehicles. And the gravity gun, oh lord, the gravity gun. . . .!!
Of course, I'd probably die in either case, withing 5 minutes of the start of hostilities. . . .
But in Doom 3 some zombie motherfvcker would rip my face off and suck my soul out of my eyesockets, and then spit it into hell where it would fester for all of eternity.
In Half Life 2, I would have fallen to my death trying to escape from the city polic on the roofs, not a good way to die, but not grotesque. Hell, I might even catch a bullet or two and die like that. Not a horrendous way to die. And then my soul has three places to go: nothingness, if there is no god, heaven, if there is and I've been good, and hell, if and only if it exists and I've been bad . . .
So HL2 is the clear winner. Relatively clean death, and only a 1 in 3 chance of rotting in hell for all of eternity.