I upgraded to a Samsung Galaxy S Fascinate from a Blackberry Curve a few months ago at the recommendation of the sales man at my cellular provider. I originally went in for an iPhone (after my blackberry crapped out) and the sales man insisted I try the Samsung, and he even said if I wasn't impressed after a week, bring it in and I can get the iPhone instead. Well I am impressed!! I like it much more then an iPhone and it is so slick, has tons of neat gadgets included, plus the Android market provides tons of apps free or for a cost (angry birds full version is free!) I recommend this phone to all my friends and I've already had 3 friends upgrade to a samsung from an iphone!
The only negative I have towards this phone is that its so thin and light that sometimes I lose it in my purse!