It varies hugely, some Economy meals I have had have been excellent, others have been awful. Same with the snack and sandwich service.

Aegean Airways has very good catering as does Turkish Airlines, and even little obscure airlines can have surprisingly good service and amenities. For example, Air Dolomiti and Luxair, both Lufthansa Group airlines.
But the overall winner is SUN-AIR of Scandinavia, a little Danish franchise airline belonging to BA, and they sure spend more than €5 on each passenger on their food and drink offering (a full meal service on all flights).
Any other suggestions of small airlines with excellent service in Europe?