This thread rapidly devolves in to people name-checking favourite airlines.
I will have flown ~100 sectors by the end of this year, to ~45 airports, about 2/3rds long-haul, and all but a handful in J or F. It's not an especially unusual year.
Service varies much more on flights with any one carrier much more than it varies between carriers. Seats vary depending on plane deployed by carrier as much as they vary between airlines. About the only constant is the amenity kits, food, and crew uniforms.
The best service I've had this year was on China Airlines (an ROC carrier, not a PRC carrier), and the worst by far was Asiana (out of South Korea). I have no trouble believing next year I'd have the complete opposite experience.
Service in any industry can be such a variable. I've sat in a restaurant and had outstanding service while watching the couple next to me get terrible service from the same server, culminating in that server accidentally crushing the reading glasses of one of the other diners. I got lucky, they didn't.
In short, in my experience: when booking flights, it's generally worth just ignoring any claims of service excellence or otherwise, and looking at the food and seats you'll get on the specific airplane you'll be flying on. I'd take the Vietnam Airlines 787 Dreamliner with the Zodiac Cirrus seats any day over a Singapore Airlines A330 with the 7811 seats, and if I was flying in Y, I'd be basing my decision purely on a combination of seat dimensions and how new the airframe was.