Looking for good anti-virus software?

Hey everyone, so I recently decided I am going to be buying a new anti-virus software. I have had problems with viruses before and don"t want to deal with it any more. I"m currently running the free versions of avast and advanced system care. I really dont mind paying for a good software. I want a software that will scan dowbloads, and block any malicious ones. I also want it to be able to clean up any possible threats, viruses, or spyware. And prederably be able to optomize computer performance. Thanks.