Deny drop permissions for all other users except actual administrator - SQL Server 2008
Use a DDL trigger to prevent the drop if the login name doesn't match what you expect. Modify the database name and login name as appropriate.

USE myDB
GO

CREATE TRIGGER no_drop ON DATABASE FOR DROP_TABLE
AS
IF SUSER_SNAME() != 'DOMAIN\username'
BEGIN
    RAISERROR('No table dropping.', 16, 1)
    ROLLBACK TRANSACTION
END