My subscriptions first, typically, off and on thru the day.
When I have a hunk of time, I start, in order with the new posts in:
Shark Tank (latest problems mods should know about, mostly spammers)
Reefs
Fish Discussion
New Hobbyists
Aggressive
Photography
Aquarium
Then in less of an order the other forums and start bouncing back to the others as well. I don't know how this pattern started but its pretty constant.
As for what posts...hard to say, some randomly, some "oh this will be bad" or just plain strange subject lines.