If you are willing to take the risk and go for a stakeholder account the best one around right now is with family investments. There ethical child trust fund account has a great rate, and you can get £35 cashback through quidco, and £25 of Boots vouchers if you set up a regular direct debit. Just be aware that over the years it may decrease in value.
Otherwise go for a cash savings type account and at least you know it will never be worth any less than it is now. Nationwide offer these if you have one near you.