Any suggestions for applicant tracking systems?

We are currently seeking an applicant tracking system for our company of over 800 employees and growing by the day. Essentially we would like to no longer use paper applications and have candidates apply online and HR to track the applications. I know there is a lot out there and they vary greatly. I wanted to get a general consensus as to any ATS that someone might have experience with and their opinions on them. Ideally we would currently like to just have application tracking. From the moment they fill out an application, til they're hired. We would also like to incorporate a system which can grow with us into an HRIS system. Thank you.