If the only requirement is beach and sun - you can't do much better than Florida (how's that for a Chamber of Commerce commercial

). Don't know what the air fares look like - but the hotels are cheap - because it's low season here in 2/3 of the state (high season up here in north Florida). And although we may not have the best luxury hotels in the world - we have some nice ones.
Do you care whether the water is warm? If not - there are some great places in California and Hawaii.
And you might consider some of the places in the Caribbean. Robyn
P.S. How old are your parents - what's their idea of nightlife?
P.P.S. I have been to beach areas in Europe and the middle east. I cannot believe what passes for a beach in most of Europe - big pebbles (even stones). And places like the Red Sea are cold - even in the summer.