Mostly user interface glitches are what bug me.
I don't like the laggy menus, the slow and awkward process to delete old savegames.

I just got killed from the unresponsive controls.

I was surrounded with full vigour and trying to press Quen and he just stood there.

It's SO annoying.

Even more annoying is being thrown into a fight straight after a cut-scene with no weapons drawn.

By the time you have control and can do anything, you've been hit several times.

Why developers do this is beyond me?