I’ve been watching anime and reading manga since I was a kid so I've become pretty picky. I've got my favourite genres but I'll give anything a shot.... for at least for 3 episodes. More, if I'm really bored and have nothing better to do than maraton a series I'm not too keen on.
Full disclosure: I love cheesy giant robot series. I'm more than willing to overlook any number of metaphorical sins a series has if there are enough cool robots and explosions... so take any giant robot series ratings with a grain of salt. On the flip side, if a series has even a wiff of fanservice harem (or Tsunderes) around it, I'll probably be unnecessarily harsh when it comes to judging it.
There are exceptions, of course.