Best Session Library

[eluser]Unknown[/eluser]
I apologize if this question has been asked a thousand times. I need a reliable session library. It will store information related to a user (probably just a user id), so it needs to be secure and quick.

I am not sure of the quality of code or the array of features in any of the available session packages, and I've heard the CodeIgniter included session class is lacking. Should I build my own or use one of the already made one?

Thanks!