Nokia E71 for £14.99 up-front plus 1p credit check, then £15 per month for 18 months, with £42 potential cashback from Quidco.
This is an 'old' phone but still a great phone in just the same way that the N95 8GB is.
3 are offering this phone and tariff online with the 50 video minutes pack (do people use this?) for £20 a month, but this will cost £360 for 18 months minus £32.50 Quidco. They did offer 300 mix'n'match with 1GB internet for £20 but not any more.
An add-on for the internet can be purchased as and when required for £5 for 1GB per month.
Works out to be £243.00 over the 18 month period, £13.50 a month.