Put it this way, in relative terms, running as root - very insecure but full control.
Running as Admin - less insecure but slightly reduced control.
Running as Standard account - more secure but much reduced control (though if you know the admin password this returns to being only slightly reduced control)
Running as Standard account with parental controls enforced - even more secure but very limited control.
FWIW, you don't have to create a brand new Standard account for yourself, you can convert your current admin account into a standard one:
Simply create a new admin account (don't forget the username/password - you might want to make a secure note in Keychain of them with controlled access). Logout of your current account (which is still an admin account at the moment) and log into the new admin account. Once in that account, open System Preferences>Accounts and select your user account. Deselect the "Allow user to administer this computer" button to make it into a standard account.
As a Standard account holder, you can still install things into the /Applications and /Library folder still but you will always be prompted for an admin name and password, even for drag and drop installs. This also means that you will never be the owner of the applications - admin will be. Hence more security.
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