You need to tell us more about your needs. There are dozens of software, all of which are excellent and highly recommended. There is no "one size fits all".
So, is it for a sole trader or limited company?
Are you selling products or services?
Do you want desktop or cloud/internet?
Do you employ staff?
Will you be vat registered? And if so will you be on the flat rate scheme?
Are you engaged in building/construction (will the CIS scheme apply?)
What's your budget?
Do you need reporting by product, customer, contract, division?
Do you need stock control?
Do you need it for customer database?
Do you take or give credit from suppliers/to customers?
Do you handle cash or are all transactions direct through the bank account?
Do you trade online? Do you have a website? Do you use paypal or other credit card processing?
The answer to the above will determine what software will be "best" for you.
Alternatively, ask your accountant as it's usually simpler/quicker to use software that the accountant already works with and they'll also be able to help you set it up and use it properly.