If I were buying a new computer and didn't want to fuss with keeping it clear of spyware/viruses/general nasties, didn't want to run demanding games and didn't want the tweakability of Windows (and all the potential problems that brings!) I'd definitely be looking at the iMacs.
I often recommend Macs to friends - and several have followed my advice and are very, very happy with them.
I'm writing this on my iBook, which I love to pieces. Go for it - you'll enjoy learning your way round the elegant OS.