Cheapest flexible repayment loan?

cooler_2

I want to take out a loan of £15,000 over 10 years. I will probably be in a position to up my repayments next year to pay this off quicker. What are the best loans (fixed interest) out there at present? I know Martin refers to Goldfish in his advice section on this - but this is currently 9.9% and too expensive for me at this stage. Also I don't want to go with Cahoot as this isn't fixed and could go up. Advice much appreciated!