Incite is more expensive, but the phone looks a little cooler (phone, not the screen)
Eternity is a bit cheaper and its a Samsung product, a win in my books. But it does look like an Iphone just a bit.
Compare them here:
LG Incide CT810
http://reviews.cnet.com/smartphones/lg-incite-ct810-at/4505-6452_7-33397476.html
Samsung Eternity
http://reviews.cnet.com/cell-phones/samsung-eternity-at-t/4505-6454_7-33394183.html