Sharp is about the only game in town for 70" - No plasma in 70" sizing and the Mits mentioned above is not a flat panel - it's a RPTV that is thinnner than in the past but simply remains ridiculously thick and fat compared to plasma and LCD.
Review the 70" owners feedback over at Amazon, Best Buy of the 70" Sharp that meets your budget and then go audition them - reading owners threads here can be tricky and as you'll rarely find a single thread here that isn't tainted by OCD owners as Happy owners often never seek out a Forum to share their experience - they just sit back and enjoy whereas threads can run seemingly infinite here with redundant posts that run on and on and the hobby or soapbox kicks in as a platform so you need to differentiate one from the other and then take what you learn that is meaningful to you and audition for your own eyes and what says WoW to you regardless of what you see here.
Some of the best feedback I've witnessed on the Sharp is the 632 series. You could probably get a 65" plasma under your budget but make sure you have the lighting conditions to make it shine. I'm 100% anti-plasma as I have a southern exposure with tall windows and I hated the one I had for the week or so I owned it as it was a reflective nightmare 24/7 that was washed out during the day that made dark video games and movies unviewable on sunny days and the dirty gray or yellowish whites truly sucked after being used to bright whites of LCD - some love plasma here and bravo for them but I couldn't tolerate it and took a sizable loss to get it the hell out of my HT. Bottom line do your homework and then let your eyes and wallet be the judge - Good Luck!