There’s no best software for all. It may depend on the type of hotel you run and the kind of property management system you have. There are several market leaders that fit large hotel chains, independent hotels, and even those who have a private home for rent.
The market leaders are SiteMinder and Cloudbeds. Both have large pools of distribution channels, Airbnb connection (not all channel managers have this one) and can integrate with many PMSs.
PMS integration must be the first criteria of choice if you have one. For midsize and large businesses, other essential things would be real-time property updates to avoid overbooking, analytics, and centralized content management to update hotel info across all channels. SiteMinder, Cloudbeds, STAAH, and eZee fit these criteria.
For small property owners and vacation rentals, you may look for Airbnb integration and well… low price. E.g. eZee Centrix and Lodgable look like the cheapest options for properties with 10 rooms. Lodgable is actually free for its main features and caters to vacation rentals.
We have a broad review of the main platforms in our article about channel management, so you may check this one as well.