Constructive feedback on my mixing?

I'm a very beginner-level mixer, just wanted to hear what you guys have to say about what I can improve on and whatnot.

I have all of them posted on my soundcloud --

Individually -- http://soundcloud.com/jalalmustafa/mustafa-mix-1

http://soundcloud.com/jalalmustafa/mustafa-house-mix-2-1-2-2012

and

http://soundcloud.com/jalalmustafa/mustafa-house-mix-3-1-4-2012

All feedback/constructive criticism is welcome! Thank you!