I have used Which?TaxCalc for several years and found it to be accurate and stress-free, just like it says. It covers the Core Return, Employment, Self Employment, Land and Property, Trusts, Capital Gains, Share Schemes, Non-Residence, Foreign Income, Partnership Income, R40. TaxCalc 2000 costs £24.99 and is on sale at the usual PC software outlets or direct from Which? on 0800 920 140 quoting TRG00, your name, address and credit card number with expiry date.
As of the weekend before last, a certain tax-office in Scotland was still waiting for 70% of the returns to come in! If that's indicative of the rest of the country, then there's a lot of panicking people out there!