There are a number of payroll processing companies to choose from, and while many of them are reputable, the best one depends on what you’re looking for. ADP and Intuit are two of the top payroll companies for businesses, with Intuit focusing mainly on providing software for small businesses. Gusto is great for sole proprietors (like freelancers), and OnPay is also ideal for extra-small businesses. And, as you know, Paychex is a prime competitor of ADP, offering payroll services for businesses of all sizes.