Depending on my location, my "perfect" changes.
For most of my backpacking, here in Washington (and by far my overall preferred system), I go for the tarp/bivy/groundsheet combo. I have the Solo Plus cuben groundsheet from Zpacks + MLD Soul Bivy + custom Cuben tarp from Ron at MLD. This gives me the most flexibility in various weather and above the tree line.
When I am back visiting in the South, I instantly go to my Hennesey Hammock Ultralight Backpacker A-Sym. Since there are almost always trees, it isn't a problem. Besides, being off the ground and surrounded by bug netting is never a bad thing. This is also the most comfortable option but sometimes susceptable to cold without an adjunct, such as an under-quilt.
For the few times I am either car camping, backpacking with a group, or staying out overnight in snow, I will take a traditional tent. Even so, I go with something light -- currently the Golite Shangri-la 2.