I almost never take a tent on backpacking trips, much preferring a tarp of some kind. I live in Southern California yet frequently encounter rain and snow in the higher elevations. My tarps have always keep me protected and happy.
Over the years the tarps have ranged from simple sheets of visqueen, to blue poly, to silnylon, to most recently, cuben fiber. They have ranged in size from 8'x10' versatarps all the way down to tiny ponchos. During the era when I was a Boy Scout (the 1960's), we never took tents on any of our backpacking trips. Our yellow plastic ponchos were simply dragged over our flannel sleeping bags and tucked in around the edges under our vinyl groundsheets in inclement weather. I don't remember ever getting seriously wet even with that primitive shelter. We also took care to camp in protected areas where trees provided much cover.
I have also occasionally slept in a bivi, with my poncho kept handy in case of rain. On one memorable morning I awoke to find a deer standing over me, oblivious to my presence. My buddies in their tents missed this, as well as all the beauty of the stars and night sky. This to me is the major reward of sleeping out. For bugs I have used a simple headnet and foam earplugs (if you can't hear them, they can't bite you). My present bivi has built-in bug netting, so I suppose that would make the headnet superfluous.
Some of the new ultralight tents are tempting in terms of weight, but put me off by their high prices. Besides, I already own an ID SilShelter, which I pack when my wife comes with me. She hates bugs, and when pitched tight to the ground, the SilShelter keeps out the worst of them.
To my way of thinking, a tarp or poncho/bivi combo is the way to go. Whenever I have to sleep in a tent I feel that I am closed off from the forest and missing out on too much.