Which of the following features is most likely to influence the order in which you read PM nodes, i.e. to read them before reading a nother node:

1) The timestamp (earliest first for replies, latest for original nodes)

2) The depth of reply level (treating an original node as 0 and having the highest priority in this case).

3) The category it lives in (e.g. SoPW, MonasteryGates...)

4) By Newest nodes

5) By Recently active threads

6) Other?