At the time, HL was pretty much an advancement. However, there's nothing to keep me playing it now. I've enjoyed countless other games both single- and multi-player, but Half Life is just a game I have gathering dust on my shelf, a relic. The day I got a decent internet connection was the day I gave up on HL and moved to Q3A... and it's been great fun ever since. Don't get me wrong, I bought HL near enough as soon as I could, and loved it for about a year, but it's old news now. HL2 will need to be something incredible if it's going to be vying with Doom 3 for my gaming time.
Still, in a year from now you'll all be playing CS 2... *sigh*