OS X has been what Microsoft wanted Vista to be since about 2003, but like Vista, it's not for everyone. This is really a matter of personal choice. I love OS X, but others can't stand it, while yet others are indifferent. Which category you fall into, only you can determine.
I will say that simply having two operating systems on the computer at a time will not cause any sort of stability problems. Bootcamp is just a boot loader. You pick either Windows or OS X at bootup, then reboot to switch to the other one. Parallels, VMWare, and VirtualPC are programs that let you run Windows in a window on OS X, but they're treated just like any other program by OS X, so if something goes wrong, you should be able to kill the process. The Unix core of OS X makes for a very solid and robust setup, which makes it unlikely a single rogue process will bring the system down.
Since it's kind of an expensive gamble to buy even the cheapest iMac model, I'd suggest looking for public systems in your area that run OS X, so you can get a feel for the OS. If you can get in before CompUSA closes half their US stores, they usually have a floor model or two. A public library might have a few, maybe you know someone who has one... Try the OS out, see if you like it. If you do, go ahead and get yourself an iMac, otherwise, buy something else.
i am very interested in getting an IMAC as i am a person who like to do graphic and i've heard many stories about the "goodness" of a mac.But the thing that attracts me is the fact that the new mac operating system LEOPARD has this program called "Boot camp" so that i can switch windows and mac altogether.but i am afraid that the IMAC would hang frequently because of the usage of TWO Operating Systems....WHAT should i do?