I don't think there was much better 5, 10 or 15 years ago or more.
I recall a flight on BA Philly to LHR in '92 which sucked chunks (sat in the middle, at the back, a drunk overweight colleague with me, rude cabin crew, crap food nowt t' do); I had a flight from HKG to MAN via Doha before Christmas which was as perfect as an economy flight could be.
Decent seat (by an aisle), decent grub (but nowt too fancy), ample drinks (I'm off getting drunk on flights nowadays anyway), great IFE system that worked flawlessly and a quiet, subtly lit cabin that seemed spacious enough.