I would probably take mostly clothes, shoes, a few books and personal items in my case, it would depend where I was going and what could be easily bought when I got there, it might be cheaper to buy some new things than ship the one you already have. But its good to have some familiar things around you as well.
I once went to West Africa for a 3 week visit, when I got there I decided to stay for 3 months instead. There is a difference in what you can do without for a few weeks but would like to have with you if you are away for 3 months! (Though my biggest regret was in telling everyone not to bother writing as the post was so slow and I thought I would only be there a few weeks, then going 3 months with no news from home, there were no telephone lines from where I was.
)