For travel over the week of Thanksgiving, fly nonstop from Los Angeles to London for $689 round-trip, on Norwegian.
In addition to hand baggage, the fare you see below does include one checked bag (for both outbound and return segments). If you're the sort of light packer who can travel with only a carry-on (no more than 22lbs), scrap the $84 baggage fees, pat yourself on the back, and pay only $605 round-trip.
Anyhoo, we found seats departing LAX on Wednesday, November 26, and returning from Gatwick on the following Wednesday, December 3. You'll find other dates are also available for travel throughout fall. For a complete look at current finds from all over the US and Canada, see our listings for London LGW.