What airline do you consider to have the best/worst Business/PE Class seats?

The differences can be not just by airline, but by specific aircraft.

Best Biz: Q Suits on Qatar get all the buz—I've not had the pleasure (but I've been booked on them twice and canceled... Covid!) They have a bad rap, but I love the seats like Turkish has on their b777s and a330s—I value comfort over privacy any day. (Same seats on LOT's b787s and lots of other places.)

Seats I've loved less- TAP/Swiss/Aer Lingus/Finnair on their a330s: the 1-2-1/2 layout is noticeably tighter than a regular 1-2-1. The same goes for JetBlue Mint and Aer Lingus on the 321s. I'm flying American in a couple of months and chose Premium Economy over the business because their zig-zagged seats on the older b787-8s aren't worth it for me. I've never flown a 'herringbone' seat—back to the window, feet towards the aisle—and I hope not to.

Regarding Premium Economy, most airlines have the same offering. Literally, the same model from the same manufacturer with different upholstery and another tweak or two. Lots of people hated the outgoing Air France seats, but I didn't mind them.

I love British Airways' pods, and their food is very good too. The pods have pull up frosted partitions so you are in your own little cubby. J

Best business class- hands down Emirates.

Best premium economy - still searching.

Worst first class on international flights- Delta.

We mostly fly Delta internationally and have had good seats and rock hard ones depending on the age of the aircraft. Since I fly out of Albuquerque Delta or United is basically it for choices. Some day I'd like to have enough miles to do something.

For PE, one must pay attention to whether leg rests are available. Some airlines offer them to front row seats.

Without flying dozens of different airlines on numerous routes in different craft, all you are going to get is opinion based on limited experience. And then is it the amenities, the bed, the little door that closes or almost closes? Too many variables: one flight on airline A but seated too close to the galley, another on B but your video monitor screwed up, another you got one crabby steward....

Ultimately, Bets is quite right. (Though there haven't been 'stewards' on flights in over 30 years.)

There are lots of bloggers that do comparative analysis of airline products. They're mostly trying to sell credit cards, but the information can be useful. 'One Mile at a Time' is one of my go-tos.

"Worst first class on international flights- Delta."

Well since they took out First Class decades ago that problem is solved.

So here's my short vote

Premium
1. Virgin Atlantic
2. Delta
3. AirFrance (and I feel certain if I had others to compare to they would be dead last. Dreadful seats and they apparently use them on all planes)

Business
1. The new Delta Suites
2. Virgin Atlantic
3. Air France
4. Some of the older Delta planes
5 British Airways

Qatar (Q Suites) followed by Emirates.
the q suite pods and their service and food is fantastic
Emirates does not have suites (atleast the ones i flew) - otherwise I would rate them on top. their service and food it out of this world. but if you fly their A380, they also have a proper bar in the middle. its feels royal.

Air France PE has dire seats. There is no proper recline, only a "butt slide" that makes you slouch. With the upper body still upright, sleep was hardly an option...

Check SeatGuru for the aircraft flying on your chosen route. It will tell what aircraft the company is using on that route and the seat configuration. They will also give an opinion on which seats are better or worse.

RE: Air France PE. B787's and A350's have "normal" (ie, not the abysmal "butt-slide") seats in Premium Economy. They are starting to remove the abysmal seats in B777's, so until that retrofit is complete across the entire fleet one might get a new, comfy seat--or one might not.

https://www.flyertalk.com/forum/air-france-klm-other-partners-flying-blue/2080586-improved-added-premium-economy-af-kl.html

Great Business Class seats:
All Nippon Airways' "The Room" -- which beats many airlines' first class seats
Qatar's "Q Suites"
BA's new seats (sad that they don't offer these on many US routes)
Swiss' and Austrian's 777 -- only the "throne" seats, which are single seats with two side tables
Air Canada's 1-2-1 new seats

Bad Business seats:
United's 2-4-2 configuration
Lufthansa's 2-2-2 configuration
BA's 2-4-2 configuration
Singapore's 1-2-1 configuration -- many people think highly of Singapore Airlines, but their business seats are not comfortable as you must sleep at an odd angle
Emirates' 2-3-2 configuration