What about Half Life 2?

I've not played the HL games yet, I'm waiting 'til I have them all to start ^__^

You should definitely go with Opposing Force next, it's a great expansion with many new things added. After that you could try Blue Shift, its nothing ground breaking but a nice add-on to the main game. As for Black Mesa i would recommend downloading the free mod version: it's the recreation of the original half-life with the source engine, they added many details to the levels but there won't be any new areas. Also while i think its great as a mod, for me it lacks that half-life feel the original had. (Oh and don't forget downloading the "On a rail uncut and the "surface tension uncut" maps for it as the original lacks a good chunk of the two levels).

I would also like to know the order of them :)

YOU, SIR, NOW KNOW WHAT IT MEANS TO LIVE!!

I mean half-live ( ͡° ͜ʖ ͡°)

But seriously, welcome to the massive club. This is one of the best franchises ever. Period.

I recommend playing Opposing Force next and then Blue Shift after that. Then move on to Half-Life 2, Episode 1 and Episode 2.

Blue shift is meh, 4 hours of gameplay, nothing speacial for me.
Opposing force is good, it takes 14h to finish, has new guns etc. Go for it.

I would go for 2 directly . Have Opposing Force and Blue Shift but haven't finished them and HL2 is really really good, you'll have much fun.

Opposing force > blue shift > Azure sheep mod.. How blue shift should have been! Best mod i played for many many years when it was released. > HL2 + EP1-2

Also the demo for Half life was quite neat.. Uplink or w/e it was called. Loved it more than most of the original game due to the layout.

I bet you can finish all of them before HL3 comes out...

I didn't make you do it this time.
Or the first time, for that matter.
Just the second time.

opposing force is quite lovely also blue shift is cool :3

Lost coast should be from hf-2 so that could be done later

I applaud you. I couldn't play it for more than an hour the few times I tried to get into it :/
Dunno why.

dude, half life 1 was genius... what ever you do, dont play hl2... its not even near being genius as hl1, and by some weird paradox, its praised like hell. :)

I'm half way in Opposing Force :)

Black Mesa is Half Life 1 remastered, but it doesn't have Zen yet (the alien place). I'd say play Half Life 2 next, I didn't really enjoy trying out OF or BS.

Lost Coast is only a test game. It's not an actual game in the series.

Opposing Force -> Blue Shift -> Half-Life 2

Ignore Lost Coast, it's just a demo level with almost nothing in it. Black Mesa doesn't offer anything relevant to the game, so you don't need to play that.

I'm also playing through the original Half Life for the first time. It's been fantastic so far, I have gotten lost in a few parts though and it unfortunately got put on the back burner after Isaac Rebirth came out.