Any preference on display type. LCD, LED, Plasma? Any features you want built-in (web browser, netflix, monitor input, total HDMI slots, etc.)?
LEDs are pretty hot now.. low footprint, super thin and nice image. Low energy cost and long shelf life.
I prefer LCD myself, but that's just me. I live and work in lowlight conditions so the LCD backlighting isn't as iris burning as the LEDs.. hehe. My LCD is only 3" deep, so it's not like tv depth is a major factor.
No matter what, you'll want a high contrast ratio, 5000:1 or higher. Make sure that's "static" and not dynamic ratio. Most sets today range in the tens of thousands so no worries there really (movie theater is a 500:1 as comparison).
Refresh rates at 120, 240 & 480 are commonplace nowadays. I have a 120Hz rate on mine.. and I have no complaints. 3D requires at least a 120Hz rating.
Don't let them sell ya a 60Hz rate if you can avoid.
LED obviously holds all the advantages (other than price).. but it really depends on personal viewing and features preference. My friend swears by plasma, while I always argue LCD over anything
As far as brands though.. that's one thing my friend and I agree on. Samsung.