Well, I try hard to include only reliable information into my own database (built from scratch since 2000) that is the base of my website at:
http://www.aboutnames.ch/
Of course this site here - BtN - is a source that I consult frequently and whose reliability is beyond doubt for me.
The "Baby Name Addicts" also state a goal of reliability on their website. There is not that much information per name but what I have seen so far seems solid:
http://www.babynameaddicts.com/
Edgar's name pages are also very good in my opinion - with this quality the site should probably get more attention than it actually gets:
http://www.geocities.com/edgarbook/
Rene
www.AboutNames.ch