Jetta TDI

I have been hearing a lot of conflicting information about weather the jetta is a good quality car to buy or just a bunch of problems. I need a diesel and there are only two manufactures to choose from. I like tghe idea of getting 50MPG but not if I have to constanly take it inot the shop. Could you tell me all the common problems associated with the Jetta TDI model, I am looking 2000-present years.

thanks