I am very much impressed by your two point perspective piece. The fact that you were able to get your lines down so well and make it believable is really outstanding. Personally though, I think I like the Sparrow piece the best. It may not have the level of detail that some of your other drawings do, but I feel like the level of emotion you captured is palpable. Also that Jolly Roger. :]
Your crosshatching is great too. It's makes for a really unique style in your drawings. It's pretty clear that you have some classical training in the artistic department! Have you taken classes or is art just a hobby for you?