Okay, i think Sara should be with...GREG!
Grissom: I think even if the impossible happens on CSI and Sara and Grissom do start a romantic relationship, it will hurt and and harm Sara (not physically btw) more than it will be good for her. I believe Sara does hold a deep love for Grisom, but i dislike comments such as "Their love for each other will be enough in the end and they will live happily ever after." (Not that i'm saying that people say that on this board) I think that a serious romantic relationship between the two will simply not work, because Sara DOES need more from Grissom besides 'love'. She needs a healthy relationship with steadyness (i'm sure there's a better word for that somewhere), laughter and fun, and not with doubts, uncertainties and a man who cannot communicate feelings and emotions well. I'm not calling Sara 'high-maintenence', or anything like that, but i believe she needs someone who can support her emotionally and Grissom cannot do this, from what we've seen on CSI.
Which is where Greg comes in. In the past season we've seen Greg asking after Sara, and actually MAKING HER LAUGH!!! (which seems to be a grand feat of accomplishment). Greg is very intelligent and quircky (sp?), he is like Grissom in many ways, but he has something Grissom seems to lack, the capacity to show love and emotion, which is what Sara needs, with all the crap she's been put through in her life.
From this standpoint, Nick is also a strong contender, but i reckon that Sara and Greg have more UST, and just seem like they would be able to have a healthy and supportive relationship. And, the fact that Jorja and Eric obviously support the Sandle ship doesn't hurt either.
Anyways, that's my two cents...