This excludes the Bible, which is a given.
I am actually generating the list by seriously reading Jaroslav Pelikan's 5-volume work The Christian Tradition, A History of the Development of Doctrine. I am on the first book that covers 100-600A.D. I am now up to only the third chapter.
Up to the 3rd century A.D. excluding the Apostles whose works are in the Bible, the key figures are: (dates are what I got from Wikipedia)
- Justin Martyr (103 - 165)
- Irenaeus (~130 - 202)
- Clement of Alexandria (~150 - 215)
- Tertullian (160-220)
- Origen (184-253)
- Cyprian (d. 258)