I must admit I didn't know you could do a normal USB PC to HDMI connection, there must surely be some limitations to that approach as USB3 isn't well designed for the latency and bandwidth demands of high resolution displays. I know some TV's support MHL, which means you can connect smartphones with micro-USB ports to HDTV's, but I never really saw any differences between the adapters for that.
The other approach would simply be to buy an HDMI adapter for the DVI / Display Port on your computer and then to run a separate audio cable from the PC to TV (this is quite easy if you happen to have optical audio connectors on both).
A third alternative is to consider using WiFi to screen mirror or extend your PC displays to the TV, but this too can suffer due to limited WiFi bandwidth and I think it requires that the TV supports DLNA.