Megabucks
For a cool $33,000,000, go to the Password screen, enter your name as DST, and enter the password 5AKCQSEBDS4.
Ultimate Password
Go to the password entry screen. Put in your name as ZARKON and use the password 8AAACAA9999. This will give you MAXIMUM money ($$billions) and instantly let you use ALL rides, shops and everything else possible!
Australia for free with loads of spare cash
Go to password screen and type name as zarkon and enten password pan6caa85t9