Why isn't my dog excited to see me?

Hey I have a german sheppard - Rottweiler cross. Now I promise you its not what it looks like. She is as good as gold with me and the rest of my family and shes fine out on walks and that. That's not what this question is about. What this question is about is shes never very excited to see me, where as she'll go crazy as soon as my dad walks through the door or such. Its not that she doesn't like me shes perfectly fine with me, she listens to my commands just as much as anyone else she just never seems very happy to see me lol. Say if we're playing with her she'd sooner run and play with my dad than me, not to say that she doesn't play with me we do play when dads not around but it seems like she'd much rather be with dad. Is there anything I can do to get her more excited to see me? Its like if I come home she'll look up then go back to sleep almost disappointed that it was me coming home and not my dad. So any tips at all?