Best Airline to Fly to Spain of routes, cost, and overall quality of service. Travelers can find easy options with major carriers like American Airlines and Iberia, which offer comprehensive schedules and direct flights. Low-cost carriers like Ryanair and Vueling can provide substantial discounts, but frequently at the expense of comfort and extra baggage fees. Another important factor is service quality; airlines that receive good reviews from passengers typically improve the trip experience. Travelers must consider their priorities and preferences before making a reservation, as the optimal option will ultimately depend on personal needs.