To me, I go for the iphone 4. But yes I'm biased.
To me, iPhone just does the things I need better. What do I need for a phone to do? Email, web browsing, camera, texting, and the useful apps are just a + on the iPhone. I had a nexus one, and I seriously hated typing on it. I thought that iPhone 3gs took way better pictures than the nexus one (I dont' know maybe it's just my eyes), and I thought the quality of the build was not as high as the iPhone (the three buttons ont he bottom of the screen were part of the glass screen and it was annoying having to press on an exact spot, also when typing I would accindentally push the back button eventually making me go back). Multitasking, I don't even care for and I hope apple doesn't either since it's a phone, why do I need a multitasking device? I never understood why people wanted multitasking to begin with. Now, when I first heard of the evo 4g, I thought maybe this would do things better than my 3gs. With froyo on the way. And I was about to purchase the Evo until I realized, I had already have a overdrive 4g/3g hotspot device so 4g isn't a big deal for me, I have an iPad, and have had iPhones since day one and the investment I've made in the appstore is too much to ditch the system for. And the one and only big deal for the evo for me was the front facing camera, but I realized how many evo users am I going to know versus iPhone 4 owners. 90% of my friends have iphones and 60% of them are moving to iPhone 4 (those numbers are not accurate, but pretty close). To me, having an iPhone 4 will allow me to USE ALL THE FEATURES to the full extent rather than having a all out powerful android device that I'd use the features for maybe couple of things.
And to each their own, but design wise, no phone is even close to looking good and having the top notch quality as the iphone, just tear down the iphone and u can tell how much R&D went into it. Come on, the metal seams are also an antenna! loool!
But if you really want a phone that does everything where u can watch flash (altho I don't think hulu even works on mobile devices), multitask, overclocking, and customizable everything (altho I think customizing is really an unnesccessary feature), then u should get the Evo.
It's kinda like buying a car, u can get a >300HP mitsubishi evo that doesn't look as luxurious, but is a track beast. OR you can buy a Mercedes, slower might be a bit more expensive, but it does good at what it's suppose to do take you from point a to point b in style. Different people will go for different things, when I was younger maybe 2 years ago I would go for the mitsu evo..