We just returned from a 3-week trip around the world. We crossed 416 degrees of longitude and spent roughly 100 hours flying or sitting around airline lounges during layovers. Visited Europe, Singapore, and Indonesia (including an 11-day dive cruise near Papua).
Business class the entire way, and the trip was actually quite enjoyable.
We ate well, got plenty of rest and sleep, and were pampered the entire time. Gourmet meals, hot steamed towels at regular intervals for clean up, sleep masks, slippers, toiletries, and a continuous supply of water and drinks with frequent top offs. Singapore Airlines is amazing and they have the best business class that I have personally experienced. The Singapore staff will actually make your bed with a pillow and duvet and then tuck you in!!!! LOL
The low point in the trip was the layover in the domestic terminal in Jakarta (terrible food and no lounge), and a couple of 3-hour overnight domestic Jakarta flights in economy class. I had the unpleasant reminder of what it's like to be packed in small seats like sardines, served food in sealed plastic bags, some big guy next to me taking up half my space, and having a sore neck from trying to sleep. We arrived in the spice islands exhausted, and went straight to bed at the hotel.