I can't help but see
Valentine as the male version of
Valentina.
I adore
Valentina but I don't know if I'd ever use it in real life. My images for the name are so huge I wouldn't want to use it on a real kid. I use it in some stories.
Plus,
Valentine just reminds me of
Valentine's Day. I feel there'd be a lot of really lame "would you be my valentine" jokes.
I know you didn't ask, but for nn's I like
Val and Vala. I'd stay away from
Tina because I really dislike it.