All I really need is rack mountable, at least 24 ports (I am trying to have everything in my house hardwired), and the faster the better.
as well as basic internet stuff I have a plex server that goes over LAN, and I am moving large files around quite a bit over the network so higher speed is good.
I don't really need POE.
I have heard about unmanaged, managed, and smart switches and I don't really know what each does.