This really depends on why you want to do this and what you mean by "minimal." And also if you have anyone else besides yourself need to take into consideration, either because they live with you or you want to host visitors.
For most modern folk, I'd say the absolute minimum would be a sleeping bag, a laptop or cell phone with internet access, and a change of clothes. Sounds like you are going for some unspecified comfort level above that, however.
What are your goals? Do you want to conquer the challenge of owning no more than X items? Do you want to minimize spending (note - many household items can be found free or cheap secondhand)? Or maybe you are willing to pay big money for perfectly engineered products, but want it all to fit in a backpack or car so you can move easily?