I think the best TV show that I've seen would be Breaking Bad.
It had a perfect blend of drama/action, and the plot was fantastic. The idea was unique and I loved the character development of Walt and Jesse. It made me get emotionally invested in it. I hated Skyler, felt bad Jesse, and had mixed reactions with Walt. The ending (I won't spoil haha) was great and epic. Many shows like Lost or Dexter are great and unique but have endings or seasons that are kind of ehh. I felt Breaking Bad was fantastic throughout.
I think that I enjoy watching Suits the most. I also like Embarrassing Bodies, Cheaters, Sex Inspectors, all the wedding shows, Jeremy Kyle because I am trash :P Apart from that, Gogglebox is good and Mock the Week and Release the Hounds are pretty entertaining.
I love almost all TV shows but I have to say FRIENDS, Community, Chuck, The Office, and shows that just make you laugh and that are family-oriented because you can never go wrong with them. I also love action-oriented shows like 24, Supernatural, Dexter, and NCIS. I need to get introduced more into shows like that, I'm open to recommendations! :D