Since they started allocating seat numbers (and we said goodbye to the unruly scrum edging forward - not illustrated any better than at Dalaman), Easyjet are my choice. It was a dream in Dalaman terms last week - we were hand baggage only, boarding passes printed off - so it was literally go through security, passport control, walk to gate, sit, board. No snaking queue moving at 12" an hour to check in, no strategic positioning and manoeuvring at the gate to get on early, just calmly walk on and find your seats. Fabulous.
I'm a big fan of Jet2 also, never flown with them to Dalaman though.