You guys who've never owned an iphone are pathetic. You point out it's antennae problem; you know around 5% of people are affected by this? I've had an iphone 4 for over a week now and I can't even figure out how to hold the phone in such a way that the calls get dropped.
Any smart person who has an iphone will be getting some sort of case for it anyways; this completely nulls the argument of a flawed phone. If someone wants to parade around a $600 phone without a case, they deserve all the problems they'll get.
As for not being the best smartphone? It sells because it's the best. It blows away every other smartphone in terms of sales; it literally shits all over everything else.
Best battery life
Best video capture quality
Best camera quality
Best selection of applications
Best OS - easiest to use, no errors, requires no external modding or tweaking
Best screen/size resolution
The ONLY thing another smartphone might have on the iphone 4 is the HDMI out capability, talk to text, bigger screen (despite worse resolution), and flash. Perhaps better network, although that entire argument is invalid as certain areas of all networks have poor reception.
People just love to hate; it happens with WoW, Iphone 4, Microsoft, etc..