The most appropriate style, finish and size of ceiling fan you choose for a bedroom is usually dictated by the size of the room, height of the ceiling, height of the bed as well as the position of the fan in the room (over the bed or not). The style of decor in the room is also obviously important. If the bedroom has 8 foot ceilings, it is usually best to choose a white fan if the ceiling is white. Bedrooms are usually smaller and less open than other rooms, so a ceiling fan will be more imposing on the room. White will blend into the ceiling and appear less imposing. This is particularly important if the fan is over a bed, which visually makes the fan appear lower. Also, 3 blade ceiling fans will be less imposing than 5 blades.
In many cases, brushed nickel (or silver) is very attractive in bedrooms...but without knowing the above mentioned factors, I cannot say if it would be appropriate for your room.
As the webmaster for one of the largest ceiling fan resources online, I offer a unique service where you can email me some pictures and I can make some recommendations. So I suggest you take some pictures of your bedroom and send them to me using the resource below.