Hello, I would go for Plasma! Plasma has great viewing angles and you get alot for the money! Please check out: http://plasmatvbuyingguide.com/plasmatv/compare-reviews.php
I spent about six months finding the best picture quality for the money I was willing to spend. Last year I chose the PN50C7000, and I love the picture, especially after using the calibration settings!
The largest screen they have reviewed is the 64" Samsung, which should be plenty big enough for most people.
Basically, I suggest going with the best picture for your money instead of the size. So, 64" for now seems to be your best bet!