I go two or three times a year as my kids live there. There are 8 non stop carriers to LAX. Norwegian as others have said is always decent value for money and a modern fleet. It pays though to shop around when you book. Often airlines such as New Zealand have specials. If it's budget you're after then try Wow airlines. Probably the cheapest to LAX but you have to change in Iceland between 2-4 hours layover). You will have to pay for 2 lots of luggage if your taking a suitcase thou LGW- Iceland, and Iceland to LAX. You can stay over in Iceland over night or even a couple of days at no extra flight cost if you fancy a bit of a two centre trip. Great if it's later in the year to see the northern lights and experience the natural hot spas!