Black Friday 2010, bought a 42" 720p Insignia Plasma from Best Buy. I was pissed at myself for not having upgraded sooner.
I upgraded to 1080p with a 51" Samsung Plasma in 2013. This TV is excellent! I still use it everyday.
This past Black Friday, I upgraded to 4k HDR with a 60" Sony x690. I'm very happy with it so far, considering the low price I paid. The intention is to get 2-3 years out of it as my main gaming and movie TV. I have a tentative plan to make my basement much cooler, which will probably entail upgrading to 70" plus, and a bit higher end TV. Just not ready to go that far right now, but I couldn't resist 4k any longer. The HDR on this TV is mediocre. But, it is a noticeable upgrade when you're paying attention.