I dont avoid anything specifically, I like anything that I think is well made and intriguing.
Can't even really think of any shows in those genres that are really popular, other than The Walking Dead (which I don't like) or American Horror Story (which I've never seen).
Both TWD and AHS had good first seasons but have been varying degrees of bad since.
There have been a lot of good sci-fi and/or horror hows though.
The best, IMO, being the most recent run of Battlestar Gallactica.
Buffy the Vampire Slayer is also a favorite of mind (and millions of others). My wife got me into when we first started dating. The first season is campy but then it becomes pretty great.
The X-Files is an obvious sci-fi/horror classic. One of the best series' ever made.
Black Mirror on Netflix is incredibe.
Firefly is a cult classic sci-fi series that is just awesome.
I'd mention Stranger Things but you've already let me down there lol.
True Blood was a great series for the most part. Bates Motel was very good.
Twin Peaks is super bizarre and not for everyone but I enjoyed it.
There's a lot out there..