actually i m thinking about buying a hard disk of 1 TB so the brand i would like to prefer WD elements or Seagate.i suggest me some more.
I take it you are looking for an external hard drive since you mentioned WD Elements. I own a 1 TB WD Elements and I haven't had any problems with it so far. I also own a 2 TB Seagate GoFlex, also didn't have any problems with it. I'm more of a Seagate guy myself though (I've been using their internal drives for years) so I can recommend you a Seagate.