With all the big companies providing users with OpenID's and basic usage and many other companies providing various levels of OpenID support who seems to be the leader in full OpenID support? Currently I use VeriSign which has been in "beta" for some time now and while I am happy with them I am sure there are other providers that offer way more control.
What OpenID provider is here to stay, offers control over everything, and is trustworthy to use?
Some links that I have found while looking up providers, delegation and OpenID: