Depends on genetics, but for most males 20% is where that cut off point should be. At 25% I believe not only you look too soft and smooth, but also it starts to wreck up your health physiologically and psychologically.
Personally, I try to never pass 16%. I usually stay at 12-16% year round, it serves me well and I believe it fits me better than being ripped not to mention I feel better and way more optimal.
Lower than that I lose strength and energy, less drive to do something, hungrier than normal, feel deprived, skip events.
Higher than that, I feel shitty and dislike myself, mainly because I don't like the way I look. Feel too heavy and I have less appetite. I also want to naturally cut at this point.
I believe this for me is optimal. As always experiment and see where it's best for you.