I show them the live wallpapers, especially the live earth rotation one.
I also show off how well google syncs up.
As well, I show off the youtube app, then that I have about 50 youtube videos downloaded.
I also show off the camera, damn good for a phone!
The keyboard, and how fast I can type on it(I can fly with this! Better than any hardware keyboard I have every used, although can't do it blind.)
Most of all, I show them how fast I can move from app to app, screen to screen, and what not... I usually do about a 2 minute demo that shows off almost the entire phone, and not once does it ever sit there waiting to load. That is the most impressive aspect of all!
Me: LG Thrill, rooted, et al
Wife: Infuse, slaps my hand away before I can root it...