That question gets directed more regularly to financial writers as well as on personal finance internet sites. The random part, would be that the question itself is meaningless. Its like asking what is a great football score, or what's a great color. The solution depends solely upon why you are asking.
For example, best color for a hunter's safety vest is orange, although an excellent color to paint your calming reading room is most certainly not orange. What makes a good credit score depends upon precisely why you are asking also.
Certain loans are far more risky than others. On the chance hierarchy, loans without any collateral are riskier than loans with hard to sell or difficult to value collateral, which are riskier than car loans, which are riskier compared to mortgages, which are riskier than loans backed by deposits. For every kind of loan, you are going to need a unique credit score. The top credit ratings will likely be required for the riskiest loans.

What's An awful Credit Score
The easiest way to start responding to the question, is to determine what a bad credit loans banks credit score is. Any score below 650 is regarded as a sub prime score. Put simply, everything under 650 we can get rid of as being a great score.

What's A fantastic Credit Score
At the other end of the spectrum is a really fantastic credit score. Here things can differ a bit more, but in practice, a credit score more than 750 is considered excellent. If you are ever turned down for a mortgage with a 750+ credit score, it is going to be for cause not related to your credit. For example, specific loan amounts might require some minimum income. In the end, no matter how great the credit of yours is, there is just no way for someone making $60,000 per year to pay off a $800,000 loan over 2 years without almost all of the money already sitting in an account somewhere.

Good Credit Scores