Absolute favourites are Sherlock, Doctor Who, Breaking Bad (definitely recommend Better Call Saul if you haven't watched it; starts slow but starts getting interesting), Broadchurch (less known but honestly amazing... not many shows got me addicted as much as this and season 3 (should be the final one) is coming out next year). And now Stranger Things of course.
Not a huge fan of sitcoms but I like watching The Big Bang Theory (which I watched from beginning to end earlier this year after having come across episodes every now and then) and loved How I Met Your Mother (who didn't). I also recommend the slightly less known (outside the UK) The IT Crowd.
Others I recommend but aren't top favourites (off the top of my head) are Orange is the New Black, Mr Robot (haven't watched season 2 yet) and Atlantis. The latter isn't well known. Unfortunately it was cancelled midway through season 2 and although they finished the season, it doesn't provide full closure as it had already been filmed. But I enjoyed it.
At the moment I'm watching Class (a Doctor Who spinoff which premiered last weekend and is off to a good start) and definitely want to watch Westworld, Outlander, and Glitch.
Speaking of Sherlock: I definitely don't suggest that American show in which Watson is a woman. I watched 2 or 3 episodes and hated it so much I can't even remember the name right now. It's actually popular though so maybe you've seen it and like it.