You get asked about jdramas and why you like them etc.

What would be your go to drama to recommend to that person (first that comes to mind & the one you would recommend the most) if they had never seen a jdrama before. :)

Without any doubt Hana Kimi! It's such a classic ❤
Bitter Blood, serious & hillarious!
It's difficult to say since a lot of my favorites aren't really the crowd pleasers or the best introduction to dramas. I suppose I would see what that person typically likes and recommend from that.

Though I feel like Nobuta wo Produce is a fairly good choice and a classic.
Like Kanra said, I'd rather give a recommendation based on what that person likes - at least in terms of genre. But the drama that comes to mind is Kazoku no Katachi, such an amazing family/friendship drama and I think it'd be fairly accessible even if you haven't watched any jdrama before. 
Nobuta, definitely, and Umi no Ue no Shinryoujo