I'm inclined (after conferring with the powers that be) that the best way to tell would be to go by percent change of body weight. Since all bodies are not created equal, the person with the least amount of body weight remaining at the end would win.
So, take your ending weight and divide it by the ending weight and multiply by 100. This would give your percentage of body weight remaining after the contest.
If someone were to go by inches, I would say that isn't going to be as fair of a comparison. If one were to really want the best comparison of fat loss, then I suppose doing the body fat analysis before and after would be best... but who has time to go get in the pool and have the measurements for that made.
Anyhow, thats my 2 cents.
So, according to the two that have given totals thus far:
Skye was: (200.8/223.0)*100 = 90.04%
RM was: (212/234.5)*100 = 90.41%
Krissss was (183/201.5)*100 = 90.82%
I couldn't find information on Katesmom starting point or ending point, so I couldn't check hers.
Anyhow, it appears that Skye has the lowest remaining weight percentage, so by that, I would say, as of this posting, she is the leader.
Hope this helps.