It's not that I do not want to help but most people that ask this question are new to this and this question has been asked many time and answered many times. It get's tiresome answering the same questions over and over when all you have to do is use the search tools or look at the stickies in the proper section.
Everyone here will have their own opinion on what box is best and you will still not know what box is best for you. I personally like the Fire TVs. I like them because they are easy to get, have a quad core, 2 Gigs of Ram, 8 Gigs storage expandable to 128 or use an external drive, and I can load whatever I want on it.
Most people here like the Avov and I am sure they are decent boxes and are good if you mostly looking for a plug and play device, what I don't like about them are that they only have 1 gig of ram and if you plan on running Kodi it will push the limits. The other thing I don't like about them is that you can only install for their app store so you are limited on what you can put on the box unless you root the device which then you have no support for it anymore. For example if a new version of Kodi comes out, you will not be able to update it until they update it in the app store which may take some time.
Look for a minimum of a quad core with 2 gig of ram. Make sure that you have enough storage for what you are going to use it for or at least expandable but 8 gig should be plenty. If you have a 4K TV then you might want to get a 4K compatible device. If you want to fully control what goes on your device then you may want to get a device that allows you to load anything on your device and not just from their app store.
