Went during the holidays a couple of years ago as well. Got a decent "family room" rate at the Novotel London West at Hammersmith via the Delta Perks accor website link. At that time cheapest room I could find to sleep 4 in decent part of london was over $300/ night, but the NH offered us a family room with two big beds and a sleeper sofa for $220/night. Hotel was very family friendly with great breakfast included, like most in London at that price. It's basically ontop of the tube for easy access, and Hammersmith is a major bus hub (busses are a bit slower, but cost 1/5 as much as the tube). If you ride the bus, kids (and me) get a real kick out of sitting on the upper deck, first row where you virtually hand out over the driver and feel like your getting a rollercoaster ride through the streets of london.

Other poster gave you the list of things to see. I'd also consider Greenwhich observatory which is near the maritime museum and both (reachable via tube or bus ride) are very well done and interesting to kids and adults alike.

Lastly, consider the londonwalks.com website walks that meet in the mornings, afternoon and evenings for a quick walking tour of many of the London neighborhoods. The guides are all very good at what they do and it's just a walk up 10lb fee with no reservations to join along.

Ive done the leave by Chunnel method once before 4 years ago with the family of 5 train ride to De Gaulle airport, and when all done saved about $100 overall. Depends on train ticket prices which vary based on loads. The next trip to london two years ago, looked at it but the train tickets were higher and didn't make sense. Only problem is that it is sometimes harder to judge the loads in Paris as we can't see who is cleared there like London.

Hyde park "winter wonderland" is loads of fun for adults and kids. Its a Bavarian Xmas market, amusement ride park filled with ice rinks and beer gardens with free live music all night long. Great times!

Thought I'd necro this thread instead of continuing the discussion in L&G. I'm planning on going there soon and found AirBnBs are significantly less expensive than hotels, hopefully the quality is there. Planning on 3 days in London and then zed fare on Aer Lingus to Dublin for 3 days. Don't plan on getting a car in London, is there enough to do in Dublin to do the same or would you recommend getting a car to tour the cliffs and rural areas? I've got enough time off where I could stretch my stay to 4-5 days in either locale if need be.

We did 3 full days in London in October. Stayed in Notting Hill area and used the tube for nearly all transport. Used Uber to/from LHR.

British Museum, Tower of London, Churchill Bunker, Westminster Abbey, Pickadilly Circus and Buckingham Palace are all accessible by tube. The airport is too for that matter. Buy a day pass and it’s good for busses, too.

Free travel apps for iPhone that were invaluable for us:

StaffTraveler (real load info on other carriers)

Rome2rio (navigate anywhere using available resources)

It’s been 20 years since I’ve been in Dublin, so I’m of little use but the country is beautiful.

Dublin is nice but we’ve always enjoyed renting a car in Ireland and exploring. Easy country to navigate, distances are pretty short and all kinds of things to see and do.

Ever done the right hand drive thing? If not be sure and rent an automatic. One less thing to try and wrap your mind around.

Also, this time of year be prepared for lots of darkness, probably less than 8 hours sunrise to sunset.

I did a month in Japan with a manual transmission, my brain almost exploded. For an entire month I turned on the windshield wipers when I wanted to use the turn signal. It looks like there are plenty of bus tours where I can leave the driving to those who know what they're doing and I can just sit back and relax.

Check out London Pass; discounts on museums and tours, along with quick entry options. Don’t count on the hop on hop off double decker bus for good transportation, just use it as a scenic tour. Traffic was too snarled to make it, or a cab or any surface street mode of transit sensible for just going places. The Tube and Oyster is the way to go. Upon leaving town, we missed our train to Paris due to taxi stuck in traffic. We should have sucked it up and hauled o our bags onto the Tube! Thames River cruises were both pleasant and efficient travel. Stayed at what was a layover hotel at the time, not sure if its tail is: Holiday Inn Kensington. Expensive but great location. Air BNB next time I think

We did the rental thing for a family wedding a while ago and spent an extra week touristing around. Watch some of the narrow, windy roads; it's quite a shock to come around a bend on a road not much wider than the car and try to pass an oncoming tour bus (they hardly slow down).

Thank the Volvo engineers that the clutch/brake/gas pedal arrangement is the same. Got off an 9-hr flight in coach, hopped in a brand new S40 rental and played the 'wiper-game' and 'where's-3rd-gear' on jetlag.

Also, Ireland LOVES their roundabouts! In the states, it's "Look left, turn right". Over there, as we approached the roundabouts, the whole family (the kids 3 & 6 loved doing it) would start chanting "Look right, turn left. Look right, turn LEFT!"

Thought I’d post a brief status update. London was fantastic, we used a lot of the tips presented here. We enjoyed the Maritime Museum and the National Gallery but thought the Churchill Bunker and Royal Observatory were rather boring and over priced. Travel from LHR to downtown was easy, we took the Heathrow express to Paddington which was probably unnecessary as the tube cost significantly less and only takes a little more time. We walked and used the Oyster card all over London and Greenwich as it is easy to do and the only cheap thing in London. Zed on Aer Lingus was easy, bought the tickets on myidtravel and got e-tickets emailed to us. When we tried to check in at the airport they didn’t work so we had to get help from customer service for both check-in and baggage check. They have very stringent rules regarding carry-ons so I checked my roll aboard; however, they didn’t se to enforce any of those rules at the gate so I probably could’ve carried it on. Uber is illegal in Dublin but there are plenty of taxis and they are pretty cheap. Nonrevving back thru JFK later in the week, hopefully those 20+ delta one seats don’t get used up by then :).

A few more tips for posterity. Save your receipts and ask merchants for VAT forms for items you plan to bring back to the US. You can get a refund at the VAT office in the airport. I had forgotten about that and didn’t save any in London, if you’re at LHR the VAT office is after security near the large waiting area (terminal 2). In DUB I saved my receipts but let myself get herded through preclearance and of course no VAT office on the other side of customs. Hope the socialists put my 25E donation to good use.