What do you guys think of these...?

I'm not a huge fan of the subjects, but I think that they're good drawings. I agree with Julia that the last one if extremely well done. I liked the line movement and expression. You did a great jobs with his hands. I suggest bringing in some lighter values to make your dark values stand out more. Pushing your values can improve your drawings a lot. I like the way the eyes are done in most of them. Good job and keep it up! :)