What I really want when I fly is consistency of the product. Lufthansa is very good at this, usually. Iberia is very good at this as well, but the level certainly could be ameliorated.
I hate Air France exactly for this. One flight is great, the next one a nightmare. And, well, CDG is consitent!
Avianca amazes me every time I take them. When I started out on them they were, well, nothing very mentionable. Nowadays, there are some things larger, self declares service carriers could learn from...!