Gameboy Advance | Gamecube | PC | Playstation 2 | Xbox | Playstation | N-Gage

Unlimited money:
Get together with the bank and arrange a four year loan for £20 million. Then, meet with the bank again and select the "'Yes, most definitely..." option to repay the loan. If done correctly, you should get about £36 million. You can perform this action over and over again until a desired amount of money is acquired.