Seriously consider getting a projector and screen. They're never "smart" and are dramatically cheaper at larger sizes.
If you have a lot of devices to plug in a mixer may also be needed.
It's great but you always have to turn off the lights to watch.
Personally, I'm considering looking at computer monitors the next time I need to buy a living room display. Some of the larger gaming monitors announced at CES are so much better than my 37" 720p TV, it may be worth the cost to avoid the SmartTV stuff.
Some people have also said that a computer monitor has less lag, too. I have a VCR with HDMI output, so you can use that for tuning the channel.