From what I've heard, novice or beginner smartphone users might have issues with Android software... it's still not as elegant or user friendly as it should be. Definitely stay away from HTC devices running windows mobile.
I have to admit not knowing much about the Pre or WebOS. But in my opinion, if you want a smartphone that "just works," you should look at either an iPhone or a blackberry. The great thing about BB is that it's relatively cheap, and because of the compression it uses, you don't need a huge expensive data plan to get the most out of it. I used an old Curve the past couple of years, and recently upgraded to the new bold 9700. It may not be as user-friendly as an iPhone, but it is very efficient and excellent at what it does.