Transportation from Paris to London

Absolutely, take the Eurostar. It is direct city to city and very interesting as it goes really fast. You are in the tunnel less than 20 minutes. Book as soon as you can as they use dynamic pricing. I've taken it several times and think it is the only way to go.

https://www.seat61.com/international-trains/trains-from-Paris.htm

Scroll down to London to Paris section for useful information.

For 99+% of travellers, that is a no brainer. From central Paris to central London in around 2 1/2 hours - the Eurostar train. Book up to 6 months in advance. The farther out you book, the cheaper the tickets. Use the official Eurostar website. https://www.eurostar.com/rw-en/train/paris-to-london

Thanks for your quick response.
Do you usually select the lowest price seats?
Any advantage to premium seating?

Eurostar is great. We booked First Class seats, mainly because I hate crowds. Food was good and the Champagne (Tattinger) was free flowing. A very enjoyable, stress free trip, with good lounges to wait in beforehand.

If you do book on Eurostar, make sure you are familiar with the procedures and timings.

For instance, you need to clear security and immigration in Paris before going to London
and vice versa, so you need (not should, but need) to be in the station much farther ahead
of time than if you were just getting a train to go within France.

Eurostar is not cheap, but the advantages usually outweigh the costs. The trains run from
Gare du Nord <-> St Pancras.

On a lighter note, if anyone knows a bus to take from Paris to London.....

Eurostar in about 2.75 hours.

On a lighter note, if anyone knows a bus to take from Paris to London.....

Sure. Flixbus. Paris Bercy Seine station to London Victoria Coach station. Takes around 9 1/2 hours.

Advance ticket purchase is strongly advised on Eurostar. The further in advance it is generally less expensive.

There is no advantage to getting premium seats in my opinion. I mean yes, the first class area might be a little bit less crowded and you get some perks, but the seats are very comfortable in second class, and for a 2 1/2 hour ride, it’s not worth it to pay the extra cost of first class (at least to me it’s not). And it can get pricey.

As others have said, make sure you book early for the cheapest seats and you’ll have a lot better choice of seats to choose from. You can also get a seat at a table if you like.

I agree with the others, EuroStar is the best option on that route. Taking the quickest option is the best use of valuable holiday time (IMO).

The Flixbus at least allows you to take the ferry to Dover to see the White Cliffs (and some people, even on this forum, do apparently want that experience), but the 90 minutes you lose on immigration at Paris before boarding the train you lose at Calais instead, and you start at Paris Bercy Bus Station.
The 90 minute wait at Calais is one reason the bus takes so long, apart from the train being able to travel at 2 to 3 times the speed of a bus.
Bercy is really and totally not the best end to your Paris time, even if you are willing to spend the extra time on bus versus train.

If you choose a Eurostar Snap Fare (where they allocate you a specific morning or afternoon train at 48 hours notice, rather than you booking a specific train) the flixbus isn't even the cheapest route.

Whether Bercy ever was a decent bus station is lost in the mists of time, but now it's your worst nightmare of a Greyhound station, on steroids. For anyone who really was set for whatever personal reason on the bus/ferry route I would say to take the bus from Lille, with a train from Paris to Lille.

Check out (f you can put up with all the ads) this You Tube video of the Eurostar from Paris to London.

As someone who has booked premium seats, I’ll tell you the biggest advantage and the reason I booked them was the flexibility. Now I was traveling on business when I did it, but the flexibility was what we needed so that’s what I booked.

Amplifying shoeflyer's warning, note that in high season, passengers have been ordered to begin their immigration and customs PRE-boarding formalities 90 minutes ahead of departure. Boarding has been denied for some latecomers. You need to check online for the exact time interval on your departure day, because it does change.

Pricing is like air tickets, with day-of walk-up tickets particularly expensive, if they are still available.