choosing a center channel

Hmmm. I assume you've ruled out some of the obvious things, like speaker wire reversal, a blown driver, or an incorrect setting or malfunction with your AV receiver or surround processor. Have you tried manually increasing the center channel level? My auto-setup always sets the center channel too low for my ears, causing the dialog to get lost in the rest of the soundtrack.

I was trying to find a product I saw a few years ago, that is basically a flat, planar speaker disguised as a painting. You hang it on the wall under or above the flat screen TV. I couldn't find that product, but I did find this, which looks pretty cool. I don't know how much it costs or how it sounds.

http://www.jamo.com/na-en/products/a-804-description

Please let us know what you end up with.

have you considered either a midrange psb (e.g imagine line) or kef xq (great deals on their products at accessories4less)--both make excellent centers-- very transparent without being sterile or over-analytical. for ht use, i wouldn't overspend just for appearance's sake--either of these more "mainstream" products should serve you very well.

Still not sure what I am going to do.
Over the weekend, I was able to find the local psb guy who has a couple different choices that I could demo overnight.
I also thought that I would look through the internet direct offerings that offer in home trial but didn't see anything. Av123 has one but it is a little too tall. Axiom has one with a footprint that I like but it was reviewed as being overly bright and that is what I am trying to get away from.
I am also going to call my local audio physic rep and see what he has.

If music were the driver, an identical speaker, as suggested by Kal, is the way to go. I say go all the way...surround speakers also.

However, if it is just for dialog in movies, a speaker optimized for dialog is best. Such a speaker will have limited and non-flat frequency response.