I don't think she is always selfish...being a medical shinobi, I think that calls for her being somewhat selfless. I think her flaws with Sasuke/Naruto show her as being a very well-written character.
Sasuke. I only say this because not only is he more powerful, but the entire series revolves around Naruto/Sakura's love for Sasuke. They even make it known to Sai how much they cared for Sasuke.
Plus, Sasuke is hotter :p
Well I am new here. Thought I'd introduce myself. I am 23, live in the US Midwest. I came here recently because I was sick of filler anime episodes to read the manga. So, hi lol ^_^