One of the great things about Bitcoin, is that there is no way two reliablely produce a top 100 richest list.
EDIT: the top 100 richest list you have on your site could all be owned by the same person, or could all be owned by persons who are very far from the top 100.
Even though it doesn't mean much I still like it.
Not only could 1 person own many of those addresses. The coins in 1 addresses could be part of mtgox or mybitcoin balances and owned by many people.