Greetings from Lithuania.
"Orange Is the New Black" season 1 highlights were acting and writing in my opinion. There isn't a bad or weak performance in this show, which contains many characters, plausible characters. Every single performance, main or supporting so side is amazing - this has to be one of the best acted series i've ever seen.
Writing is the next thing i admired the most. Not story itself, but writing. This isn't a very involving story at the first look, but that is because of possible and realistic story - it is not overdone in twists and over the top story lines which would made this show not realistic - and this is were great writing comes first - there isn't a dull sentence in the whole season 1, every dialog is involving, realistic and just the way these people in this place would (and are) talking.
Ovreall, i will definitely watch season 2. I liked season 1, but there were some episodes during mid season which were more like "fillters". Nevertheless, this is a very good show so far, maybe not for everyone, because nothing much in it happens, but that is one of the points - try to create a show set in prison, were no one tries to make an escape aka. "Prison Break" fantasies, and it's just interesting to watch it nevertheless - "Orange Is the New Black" is smart, very realistic and plausible, sometimes funny (but it is not a real comedy overall) show. I would say season 1 is 8,5 / 10 in my opinion. Will definitely see season 2.