The legal owner is the person lending you the money to secure the car. In your case it's the finance company. Someone above said that insurance companies pay little to no attention of the legal owner status, this is wrong! They wouldn't ask if they didn't want to know who the legal owner is. If you lie on your insurance you may invalidate it and they reserve the right to cancel the policy or refuse to payout in the event of a claim. Also, if you check your finance contract you will probably find a clause in it that states you MUST tell the insurance company that they are the legal owner. So not only do you run the risk of invalidating your insurance, you are also in breach of contract with the finance company, who may demand its immediate return under repossession AND demand that you pay the outstanding amount on your contract!
Do not mess about with this stuff, always read your contract and get things right. It ain't worth the risk!.