ParadigmDawg,
what is your room lighting situation?
Truthfully, other than screen size, it all boils down to whether you have a dim/dark room or a normally lit to bright or sunlit room.
If you're ok with the smaller 65" screen size, the Panasonic plasmas are the best consumer displays on the market at the moment. They have the deepest black levels, pretty darn accurate color, perfect screen uniformity and perfect off-axis viewing. With the new louvre screen filter, they even perform pretty well under normal room lighting - but only in cases where the light source is overhead. So just keep that part in mind.
If you have a bright or sunlit room though, or you have normal room lighting, but it's coming from sources that are not strictly overhead, then a good, matte screen LCD is the better way to go, and Sharp is about the only option right now for very large LCD screen sizes with a matte (or at least semi-matte) screen surface!
If you are in a dim or dark room, there is no competition. The Sharp LCDs have lighter black levels, the odd bit of uneven or "blotchy" backlighting, and no matter what the lighting conditions are, the off-axis viewing is a lot poorer looking than a Panny plasma. But under bright or sunlit conditions, the matte-screen Sharp LCDs still retain their black levels better, reject the ambient light better, and you can really crank the light output on the Sharp LCDs if you want to, so they can overcome bright lighting far easier than the Panny plasmas.
Personally, I'm still a bigger fan of last year's LC-70LE735U (3D) and 734U (2D only) models vs. the 745U and 845U models of this year. That's all because the 734 & 735 models used full-array LED backlighting, rather than the edge-LED backlighting found in the 2012 models. The screen illumination was more even and the black levels were deeper on the full-array 2011 models. That said, the 73xU models did suffer from some banding and posterization (false contouring), which the 2012 models seem to have resolved. So it's all a matter of which picture artifacts you find most objectionable
I have a 60" Pioneer Kuro plasma and the 2011 70" Sharp LC-70LE735U. I use the Kuro only in dark conditions and pretty much only for Blu-ray movies. With those restrictions, it beats the pants off the LC-70LE735U. But I use the 735U for "lights on" TV viewing and for playing videogames as well as for any 3D content. Under those conditions, the LC-70LE735U actually looks better than the Kuro! With the lights on, the Kuro's super deep, beautiful, inky blacks turn grey and the picture looks washed out and dull. And the Kuro has a pretty good ambient light filter - about equal to the ST50 or GT50 Panny's of this year. So it's still pretty easy to make the plasmas look washed out, grey and dull with just normal room lighting. For 3D, being able to really crank out the brightness is a big plus since the 3D glasses cut about 60% of the light!
So the point is, both the Panny plasmas and the Sharp 70" LCDs have their strengths and weaknesses. It's really all just a matter of matching the right type of display to your lighting environment. I'll take the plasma in a dark theater every time. But under well-lit or especially sunlit conditions, I much prefer the black level retention and semi-matte screen of the Sharp 70" LED-LCD.
The good news is that these really are your two best options in displays right now. Samsung's up there too, but their plasmas definitely can't handle any amount of ambient light, and all of their LCDs have super glossy screens that render them unwatchable - at least to me
I can't stand seeing my own reflection clrealy looking back at me from any dark portion of the image on screen
So stick to either a Panny plasma or a Sharp 70". And just decide based on whether you typically watch with your room dim or dark - in which case, go Panny plasma - or if you watch in a well lit or sunlit room - in which case, go Sharp 70".
Easy