I'd vote for Gmail for security reasons. Changing your information on Gmail(esp.passwords) is more protected. It is on a different window that requires your password separate from your already accessed account.
Whereas on hotmail, once anyone logged in, they have access to change all you information. Besides, hotmail suffered from a vulnerability in the password reset service that allowed remote hackers to reset your password...though a fix exists now.
check this out: Report says Hotmail exploit "spread like wild fire," is now fixed | ZDNet