I can't really give any good advice, since I read every thread, but the ones that I find the most interesting, are the big threads like It's oh so quiet and the Nature photography thread, as well as any thread that seems to be somehow informative. Of course the ones I've recently replied to are important to me, too.

The ones I just scan through quickly, are the ones dealing with some kind of drama or new acquisitions. But I don't usually miss anything really important. If a thread contains something interesting, then somebody is sure to keep it afloat.