I follow a lot of people. I think it depends on what you are looking for on a Twitter feed. Do you want a lot of current events and politics then you could follow the major networks and their anchors. If they are on there you can follow bands. I follow Nickelback and Hinder, two of my faves. And there are tons of celebs to follow as well.
Here is a small listing of some that I follow.
@Nickelback
@hindermusic
@wilw - Wil Wheaton
@DeathStarPR - Public Relation firm of the Empire
@JediOrderPR - Public Relation firm for the Jedi Order
@grantimahara - One of the MythBusters
There are others as well like the 4 main cast from Castle. Just gotta get on there and search.
And I am @Athenaonthefly on Twitter.