I was literally just having this dilemma! I'm one for always trying to see an anime through even if I wasn't really into it but nowadays I just don't have the time to watch as much as I use to. In the end I decided I had to be picky on what I watch. But hey, maybe in the future, when I'm in an anime slump I can return to the ones I've dropped and resume them. Just to say I did it.