Roger Davies
Reasoning: We don't really know much about Roger's personality, except that he's been a romantic interest for Cho Chang & Fleur DeLacour and goodness knows how many other gals. We know that he's handsome and the captain of Ravenclaw's Quidditch team. And that is all so far.
Anyway. This card symbolizes a hard working, thorough and detail-oriented individual. While they seriously and doggedly work towards a goal, they can be humorless and obstinate.
In a traditional tarot deck, this is the Knight of Pentacles.
Notes
Again, this character is one that we really don't know much about. Just that he's rather good-looking, which gets him dates with lots of good-looking witches. And I assume he's a hard-worker like this card symbolizes, as he's captain of the Quidditch team....
I don't have a super-clear mental image of Roger... I just see light, icy eyes and dark hair for some reason.... I tried to avoid making him resemble Cedric Diggory too much, by making Roger much more slender and sharp-featured.
This card was very problematic, and I think there's an awkwardness about it that shows. I couldn't nail his pose, and even know I'm not especially loving the way he's standing. However, the saving grace of this card is the colors. I LOVE THE COLORS. It's always been an irritant to me that the movies nixed the blue & bronze combo for blue & silver. I honestly don't know why they felt the need to do that, as bronze & blue can be a lovely combination. Coloring-wise, this is my favorite of the four Quidditch Captain cards.