Argh, which one to play!

[Malfunction]

I never, myself, beat HL. I got to "On a Rail" and stopped. Though, I have watched the guy who beat HL in 45 minutes, that whole video. I generally just wanted an idea of the game and plot. I didn't need the full blast. Now, with HL:S coming out tomorrow, I'm not sure if I really need to play HL:S before playing HL2, or is it safe to say I understand the plot enough and can jump into the Combine-infested battles?

I know you are all going to say this is stupid, even though I kind of want to play HL2 more.