|Im a girl. But I dun see why anyone would choose Priya except for her exotic looks. She cheated on Leonard, remember?|
That said, Priya's exotic looks are about the only positive thing you can say about her, really. What's more important is what kind of person she is inside, and in my opinion, it's not very pretty. She's willing to cheat on her mate, without even the slightest awareness of how severe it is, but more than that, she's completely unable to live her life on her own terms. I say this because of the fact that she's unwilling to stand up to her parents, as evidenced by the fact that she wouldn't reveal her relationship with Leonard (and further, hiding her return to India from him), preferring instead to stay on "mummy and daddy's" good side. She even threatened to break it off with Leonard unless he knuckled under to Sheldon's blackmail, remember? On the other hand, Raj, for all his insecurities and other issues, is much more willing to face his parents down, speak his mind, and tell them that he's living his life the way he wants to live it. Granted, it doesn't always work, but at least he's got the guts to try, as opposed to his comparatively weak-willed sister.
Take all that into consideration, and I'd pick Penny (or Amy or Bernadette) over Priya in a heartbeat. I couldn't live with a beautiful face that hides an ugly soul.