u-joints
 

i have a bad u-joint on the passenger side. the driver side seems to be ok. Is it recommended to do both sides or am i safe just to do the one?

If the other side is still good, it can wait.

I wouldn't say you're in danger, but fix it when you have the time :)

Replace them with only spicers or you will be doing them again in the near future.
http://www2.dana.com/expertforms/dek350.aspx