Basically you said it for me. I never downloaded stuff, I never went to harmful websites, I always used expensive and really good anti-virus and anti-spyware software, and my PC's just NEVER WORKED for me. Constantly had pop-up windows and error messages and frozen screens and felt like all I did was "control+alt+delete" all day long. I'd have to do a complete hard drive format and windows re-install every 6 months just to keep the thing running. I would honestly say that 50% of the time I was actually using the computer, the other 50% of the time I was just trying to fix the problems on it. I finally had enough of losing so many hours of my life to keeping my computer functional so I switched to Mac. Since then (also 3 1/2 years ago), I have not had a single problem.
Macs are also extremely easy to use. If you want to know how to do something you just think "what would be the most simple, and common sense way to do this?" and usually that's the answer. All the things that are a huge headache with Windows are just so easy on Macs (home networking, file sharing, contact/calendar/email syncing, etc)
I'm on my MacBook Pro right now and have had it unplugged for a couple hours, and it says I have a couple hours left before I need to plug it in again. (Since you asked about battery life)
I can understand that some people would prefer a PC for economical reasons or because a Mac isn't compatible with their computer needs (gamers, computer programmers, etc.). For things like word processing, photo editing, video editing, organization, email, internet, and regular daily things, Macs are very no-nonsense and simple.
The extra thousands I've spent to keep Macs instead of PC's has been well worth the thousands of hours of aggravation I've been spared.