BusbudBusbud is quickly becoming the go to site for bus tickets around the world, as it's adding more inventory to its database. Currently there are many routes in Europe that you can search, compare and book bus tickets directly on the busbud site, otherwise you can view schedules and prices and get redirected to the bus companies website to purchase your ticket.
Very soon, there will be some new bus routes added for Spain and Turkey as well as some other countries around Europe and the world.
Also another thing to keep in mind is that there is no additional fees for booking on busbud, the price you will pay is the same as on the website of the bus company.