Prison Break fell off hard after season 1 and then got even worse after season 2. As long as you finished S1 and S2 you are good.

Vikings falls off quite badly too towards the end of S4. As long as you have finished seasons 1-4 you are good.

Breaking Bad gets better and better. I recommend continuing as the pacing does pick up. It is a very good show throughout.

>a lot of other less known shows. Even try watching a single episode it's difficult, because the tought of watching it gets me so bored that I never start to watch. What would you do in this case?

It's not ideal but maybe put some scenes in 1.25x or 1.5x speed. At the end of the day all that matters is if you enjoy the show, it isn't an assignment.

There are many shows people love that I thought were pure crap and dropped. Some I forced myself to watch and just ended up wasting my time. Media is subjective.

Who knows maybe you might enjoy them some time later. They just aren't for you now.