Samsung SpinPoint F3 1TB or Samsung Spinpoint F4 2TB (but 5400rpm).
You are gonna paid more for 7200rpm drives larger than 1TB. And really not see any benefits.
See THG Review of Hitachi's 4TB HDD
In the end, 2TB were better and cheaper, the last page pretty much sums it up:
Three terabyte hard drives continue to offer the best cost per gigabyte of storage space. Two terabyte drives offer even better value at similar performance levels. Four terabyte disks are a good option when you need big capacity and don't have space for multiple 3.5" devices. However, their price premium keeps us from recommending broader adoption.