XCOM Enemy Unkown: Vanilla or Enemy Within?

I would say start with Unknown a bit first. Less features = less to learn.

And it's a bit hard to go back to Unknown after playing with those new Within features.

Oh, and EW adds new missions too.

i would go for enemy within right away.

Enemy within with the Longwar mod. really, no other way

Just a friendly reminder: there's still no hidden giveaways here.

Finish Enemy Unknown first. XCOM has great replayability, and you'll better appreciate Enemy Within on a second playthrough.

You'll spend over 20hrs on your first playthrough for sure. So that might be something to consider.

If you have the time though, then it's an easy decision.

I grabbed the game last winter holiday sale, but didn't really give it too fair a chance. At that time, I wasn't used to games that made you treat your characters as expendable. Oddly enough Shadowrun Returns made the gameplay more tolerable to me, although I did't really start playing again until the whole GMG/Playfire promotion. I'm presently six hours in and enjoying it vanilla. I might grab EW later on with my coupon.

Definitelly vanilla. I played around 50 hours of the original and bought Within on launch. But they fucked up some systems so hard, i couldnt’t even get throu first couple of hours.

I think you should start with enemy within because it just expands a lot of the gameplay features. This expansion is so well integrated that you'll probably not notice what is EW and what is the base game. As you are new to tactical games i suggest you do the tutorial and play the game in an easy dificulty. After you mastered the game you should try the long war mod. It's harder but much more satisfying to play.

I thought EW had it's own story and stuff? :o

I highly recommend straight-up playing Enemy Within. It's all Unknown has to offer, and many, many great stuff added. I bought EU over a year ago, and waited until I get EW. I don't regret.

"As I understand, EW doesn't add new missions"
Actually, it does. There's a few scripted ones that are integrated within the main storyline, and the Exalt have their own mission types. I'd go with Enemy Within, even though I do think some of the new stuff could be handled better. (Mec troopers are really kind of overpowered, and the medal upgrades work kind of weird.)