Jet2 seemed to have regular 3 hour+ delays to eg AGP this summer (much more than that both ways for me), almost weekly. Their prices for next summer are attractive but I'm hesitating to book anything if it means losing another night of my holiday and endless hours of hanging about at airports.
EZY are not at all cheap and don't deserve to be called a low cost airline, but I have to say I've never had a problem with their flights.