Fantasy
The Sword of Shannara series has a a few omnibuses available. The first trilogy was mentioned earlier:
The Sword of Shannara Trilogy
Amazon
Page Numbers Source ISBN: 0345453751
ASIN: B000FBFMZM
The Heritage of Shannara (Four Books)
Amazon
ASIN: B001O1O6RW
The Voyage of the Jerle Shannara Trilogy
Amazon
Page Numbers Source ISBN: 0345492862
ASIN: B005PRJN8S