I tend to think that third person past tense is best person in most cases. Within that umbrella, I'm also most partial to adopting a limited point of view.

You can do some fun things with first and second person, but overall it's more work than I find most people are interested in.

Third person presence has an unfortunate habit of annoying me in longer length RP posts, but it does make quite a bit of sense to use when an RP is very fast paced, uses table top mechanics on each post, or is being played out on some other medium.