For me, the best time to meditate is before sleep; it makes you feel so peaceful and it helps you sleep faster when you do it right. It could be any time of the day but it's best to have a certain hour to do it so it becomes an easy habit
I like to meditate right after my morning routine, I get up drink a glass of hot water, use the bathroom, stretch and then meditate. I find that if I try to meditate before my routine I'm inclined to fall back asleep or be distracted by thirst or the call of nature. Stretching just before gives me a stronger feeling of connection between my mind and body, which seems to facilitate deep breathing and aligned posture.