I also have a Panasonic TV (2011 Vierra with 1080p whatever - smart tv?). I don't have a wireless dongle for this device, but even if I did, it would not be of use with Plex (There is no Plex app for Panasonic TV's - only LG and Samsung have them).
I would like to stream video to this TV as well and considering that the Plex Media Server is already running on the PC, it seems that I need a device that will run the Plex Media Player, connect to the TV via HDMI, etc.
The Plex android app runs well on a Nexus 4 but I'm not keen on using the phone to output a movie to the TV (I think this was possible until the recent 4.2.2 update - I don't know much about this). I have also tried the app with a cheap Chinese tablet (Ainol Advanced I) but the wireless connection between tablet and home network is not good enough for smooth video streaming.
Can anyone suggest a device or an alternative solution?