Help me out here as I really don't know a lot about TV's.   Looking for it to be around 50-55 inch screen, built in wi-fi, and if possible 4k but I know with my budget its probably not going to happen.   My max is $600. I'm pretty open to any reliable brand except Vizio.  That was my last TV which broke and they kind of dropped the ball on their end so I would prefer not to buy from them.

Good luck getting anything decent in that price and size range with those additional requirements that isn't a vizio.

http://www.vizio.com/tvs/eseries/e50ud2.html