I have come to realize that I need another external drive to use with my MacBook Pro. I currently have a 1TB WD MyBook Essential that I have been using for about a year and a half. I have it currently partitioned into two drives, one for backup (I named it Leonov) and one for movies, TV shows and other large files I don't need very often (I call that side Discovery One). I use Time Machine for backups since it is completely automated and I can restore from it without much trouble (I have had to at least three times now). As of now, Leonov is full enough that every backup deletes an old one and Discovery One is approaching it's limits. I would like to get a new drive and move one of the sides to it.

What are some reliable, external (~1TB) drives for under or around $100? Would it be easier to move the movies (et al.) or the backups to the new drive?

I also feel like I should say that all of my important documents (for school and the like, just not my music) are also synced to Dropbox as another form of backup and access.