I would look at these models then:
Samsung 40" 1080p Flat-Panel LCD HDTV** (LN40A550) much more expensive than A500
Sharp Aquos 42" 1080p Flat-Panel LCD HDTV** (LC42D65)
Sony Bravia 42" 1080p LCD HDTV** (KDL-42V4100)
Panasonic 42" 1080p Plasma HDTV** (TH42PZ85)
Just remember that LCDs will look much brighter in the ultra bright showrooms when compared to plasmas, but in home lighting they will look much different. If you ran those LCDs at those brightness levels you would burn your eyes out in a dimmer room.
Also make sure you check out the NEW Panasonic plasma model TC-P42S1. I think you will be impressed based on what I have read. You might want to look at the SETTINGS link in my signature for a rough idea of where the settings should be at.
Hope this helps!