text and ntext types do not store unlimited data. text can go roughly up to 2GB and ntext upto 1GB.
As SriRamaKrishna pointed out, text and ntext both data types would fill the purpose. However, logically they are used to store textual data of huge size. When storing such things as Word documents or images (read binary data), it's best to use the image data type. image can store binary data of roughly up to 2GB.
For binary data of small size, using binary or varbinary (both roughly up to 8KB) is much more efficient.