At this point, I'd identify those who make it through my exclusionary sieve (declared, and active, and serious, i.e. not Teh Krazy and with any real shot at all) as, in alphabetical order:
If I were to make an endorsement (I don't plan to), and if I were to base that endorsement on ideology, it would be a tie between Gary and Wrights. If I based an endorsement on factors other than ideology, Wrights would be the clear winner for several reasons, among them that I have worked with him on a daily basis for a decade now and consider him nothing less than a brother. And, in fact, by way of disclosure, I am very informally advising his campaign on some "nuts and bolts" matters (not the only campaign I'm working with at the moment, but the only Libertarian presidential campaign I'm working with at the moment).
At this point, it looks like a Harris-Wrights race, and it looks like Harris is setting the pace ... but in the Libertarian Party things are, well, different. The presidential nomination contest is usually actually settled in a knockdown-dragout on the convention floor, sometimes with candidates announcing as little as a few weeks before that convention (and in one case, 1984, the candidate flying in in mid-convention after getting a phone call asking him to run) [note: See comments -- that was actually the same guy, but for veep in 1976; my bad]. In 2004, the distant third-place candidate going into the convention came out of that convention as the nominee. And None of the Above -- meaning NO candidate is nominated -- is an option. So I wouldn't advise placing any bets just yet.
Why is Harris setting the pace?
Well, Wrights is running a campaign that by "old LP" standards ain't too shabby at all -- he's contacting likely delegates, addressing state conventions, making financial contributions to state parties for their ballot access efforts, etc.
Harris, though, is definitely meeting the newer ground game standards -- more early direct mail, robocalls, actual professional phone polling, live online forums, etc. That translates into an advantage that's only partially mitigated by the fact that his positions are slightly out of phase with the Libertarian Party's direction. Specifically, he's very Ron Paulish, and the only one who gets away with being very Ron Paulish in the LP is Ron Paul himself.
If the field stays as it is, my guess is that it's going to come down to which one of these two puts the best convention floor team together. But, of course, the field may not stay as it is -- a "big name" (and you'd be surprised what qualifies as a "big name" in the LP) might jump in at the last minute, or even a smaller name might throw hat in ring in the next month or so.
So, anyway, here's a completely non-scientific Internet poll if you'd like to express your preference: