The nearest airport to Benidorm is Alicante just 30 minutes or so down the road via the motorway (A7). I would advise against trying to cut through Alicante town, it may look shorter on the map, but if you don’t get lost, you will certainly get stuck in traffic.
Flights for Benidorm are plentiful from all over the UK and Europe, with most of the big carriers and budget airlines landing there, not to mention all the charters by the big package holiday companies.
Use the links above to check each type, there are always bargains especially if you book your flight well in advance, remember the later you leave it, the more you are likely to pay, this is even truer for the budget flights. Checking back often is a terrific way of picking up a bargain by catching a new batch of seats that have just been released.
Play around with your travel dates as well, you will be amazed how a few days either side can dramatically alter the total price, very important if you have a large family or group of friends.