I've been trying to sell the iMac to myself for a long time. Can't do it.
I would love an all in one machine, I hate clutter. The iMac looks absolutely lovely, other all in one machines are pretty ugly.
I do web development, so the Mac OS would be perfect. It's kinda like running Linux but with a polished interface I guess. Git etc is all going to be lovely, with some great applications out there such as "Tower" (a Git GUI). Running Apache etc locally is going to be a breeze.
The issue is, just how much benefit would it bring to the table? Will I actually be more productive than I am using Ubuntu or Windows?
The price tag is absolutely ridiculous. However if there is nothing that looks as good and no operating system which is as polished but as functional, then perhaps it's worth it?
Been weighing it up for years, still no switch. The other thing is that I had the iPad/iPhone (more of an Android guy). One of the major points for me with the iMac would be the simple integration with the likes of the iPad, iPhone, Apple TV etc. However, I just couldn't bring myself to like those devices when I know, after using them, that there are much better devices on the market. Ok the answer is simple - get an iMac and stick to Android. In my head I'm missing out on part of the Mac experience though of not having things tightly integrated and "just working".
Sell me folks! Why should I get an iMac (and in future possibly a Mac Book Pro)? I kind of want to be convinced that it's WELL worth the money. I can't convince myself

I know it would look sexy sat on this desk right here but it has to be worth the money and I have to be productive using it. It's a huge leap. Every web developer I know goes on about Mac's all the time, how everything has been much better for them since switching. I'm not so sure.
I currently pick up the cheapest Dell laptop there is and hook it up to my 23" monitor and external keyboard/mouse. In other words, I don't need a lot of power. The main thing for me is the looks, screen quality and the operating system. The hardware I couldn't care less about - the lowest end iMac is more than enough for me... editing text files, editing your odd image in Gimp etc.