For me it's mostly older ones.... stuff like Iria, or Outlaw Star, Armitage.... things from that era.
Alot of more recent series are, well.... ehhhhhh. At some point, someone decided that every minute of every anime needed to be boobs and explosions. Either one, the other, or both, are happening at any given time. If neither is happening, it's probably the ending credits. And that just.... yeah. Got tired of that quite awhile ago so I find myself rarely watching anime these days because it's hard to find one that DOESNT do that. Granted the bit with explosions happens in even older ones, but what I really mean is series like, say, Fairy Tail, where it's JUST fights ALL THE TIME. It's an okay series and I get why people like it, but it cant hold my attention.
Instead, I end up reading alot of manga. Usually, whatever I'm reading either hasnt been made into an anime, or it's been made into one of those half-@$$ed ones where it's like 10 episodes that almost cover the first fourth of the series maybe and then just abruptly stops.
The one big exception though is horror series. But there are hardly any of those. I did watch through Corpse Princess recently (what a name that is), that was quite good, though the ending made me want to stab something.