What are some good TV shows to watch? (I'm 18. Love the genre of drama/romance/mystery/thriller. I watch shows like Switched at Birth, Finding Carter, The Flash, The Originals, Jane the Virgin, etc.)
My favorites are typically sci-fi or comedy but I do watch a lot of drama/romance stuff and occasionally mystery/thriller. For American TV shows that are still on air or are relatively new, I watch The Night Shift, The Good Wife, Grimm, and a bunch of crime dramas like Criminal Minds, Law and Order SVU, Elementary, and Hawaii Five-O. For those that are no longer on air, try watching the X-Files for mystery/thriller/sci-fi, Parenthood for family drama, and Gossip Girl for drama/romance. If you can, you should also try watching Game of Thrones, Penny Dreadful, Scandal, House of Cards, Orange is the New Black, and Orphan Black which are shows I was only able to watch a few episodes of since they're on things you have to pay for, but for the episodes that I did watch, I thoroughly enjoyed them and they all have really good ratings.
For British TV shows, you should definitely take into watching Downton Abbey (historical drama/romance), Sherlock (drama/mystery/thriller), and Mr. Selfridge (historical drama/romance). They usually air on PBS and they have some episodes on Netflix and Amazon Prime I believe.
I also highly recommend that you start watching K-Drama or Korean Drama. It's culturally different than maybe what you're used to but they can be really moving and captivating at times. There are also various genres that you can choose from but almost all of them have some element of drama/romance. You can watch them free on dramafever.com if you don't know where to look. For newcomers to the K-Drama world, people usually start out with Boys Over Flowers but there are also some good ones that I loved like My Girlfriend is a Nine-Tailed Fox, Love Rain, Dream High (don't watch the second one though), I Hear Your Voice, Dong Yi, Heartstrings (but it has terrible kiss scenes), and My Love From Another Star.
On the topic of culturally different shows, you can also try anime (Japanese cartoons). I know that they're cartoons and that only "geeky" people watch them, but there are some serious masterpieces out there. You just have to search for them.
But if you'd like to go out of your usual genre and step into my usual realm of sci-fi and comedy, then there are plenty of good shows too. For instance, Star Trek: The Next Generation is amazing! All seven seasons are available on Netflix and Amazon Prime. Actually, anything Star Trek related is good game. Anything from Stargate is usually pretty fair game too. Battlestar Galactica is cool as well. You should consider watching Firefly but unfortunately it was canceled too early despite it being really good (look this up if you don't believe me) so there's only one season and a follow up movie that's kinda meh. I also enjoy watching Extant and Under the Dome which is currently airing. And even though the later seasons kinda got iffy, the first couple seasons of Heroes are definitely worth watching. For comedy, I am a pretty big fan of The Big Bang Theory, New Girl, and the recent new show about Asian Americans called Fresh Off the Boat. Lastly, one of my all time favorite TV shows that isn't Star Trek related, Avatar: The Last Airbender. Yes, it's a cartoon (however, it's not an anime since it's American) but it can be thoroughly enjoyed by children, teens, young adults, and adults. I mean both of my parents like it and they usually don't like cartoons and both have different tastes in movies and shows. They have a sequel show afterwards that's more dramatic called The Legend of Korra, but it's best to start with Avatar first.
Okay, I'm done now. Sorry for the incredibly long answer haha!