I like when the students I'm grading get the problems right
that makes it really easy to grade (and also means they're understanding the material, I like when people understand)
when they get it wrong, unless they just don't even try, I have to go back and figure out what exactly they did wrong to figure out partial credit
It's similarly easy to grade when they don't even try but I don't like that as much because I like people to be actually trying and learning