It's easy to make a show look nice these days, so I really value good writing.

If a show leaves a ton of plot holes in the first few episodes I might stop watching it. Maybe it has some other fun aspect to it. Trueblood was shit but it was still fun to watch.

But if the characters don't make sense it's a total turnoff. Like if you have these brilliant people conducting top-secret mission, but they never use common sense because it would make the plot too easy. There needs to be some consistency.