Usually in my room by myself. I watched some dramas with my mom, sister-in-law, and a friend before.
Myself basically anywhere home or school.
By myself. I hate to watch anything with other people. And usually in my room, anytime of the day.
Alone in my room on my Kindle Fire HD
I watch whenever I can, day or night, by myself in my living room.
I usually watch drama alone in my bedroom, though I have watched a few episodes of a drama with my friends in the past to try and get them to watch it and I recently watched a bit of a drama with my boyfriend. I mainly watch drama alone though.
In my room, at my desk, which is where I spend my time 24/7 as a not-so-abled hermit who lives on her computer which has an HDTV for a monitor (26") & is where I watch my ~all my media via my TiVo & "smart" BluRay player with Netflix, Hulu, CrunchyRoll, AmzPrime, etc..

& even tho I live "alone" I use still earphones cuz it's better for my hearing (have mild issues) & so also watching media with subs came easily to me since I always prefer captions whenever possible anyways, hehe.

Oh & I too prefer ~solo first-time viewing for the same reasons (hearing & overall subject absorption being better in my super comfy earphones-connected desk, etc).

Altho I ~would love to rewatch media with someone else who could share the squee.. but alas, I kno of no such ppl, tho there was ONE person that I made an ongoing attempt with but unfortunately we only managed to get half thru YaB over a period of a few months, & well life is just too busy etc etc especially for watching media (as they would rather go ~out to do things) & multi-part media at that! Sooo that last ep we saw, was over a year ago now already.. siigh ;( 

& as for the when.. hmm, usually late nights, whenever I'm not watching my many other media addictions ;P