Which of the London passes include more of London's headline tourist attractions? [closed]

This is impossible to answer, really, because it depends on what you're interested in. Personally, I wouldn't like the Merlin pass, because I'd have little interest in most of the attractions it gives access to, but your tastes are almost certainly different than mine. I have no idea whether you'd personally enjoy Madame Tussauds or whether you'd have a better time spending that time at one of London's world-class museums (British Museum, V&A, Tate, etc...), touring the Tower of London, maybe an exclusive tour of Buckingham Palace (for which there are just a handful of tickets left in December—yes it's £85, but you get a small group guided tour of Buckingham Palace), or perhaps a West End show. Or maybe you'd like the London Transport Museum or the Churchill War Rooms or Bletchley Park or a tour of Parliament or a shopping trip or high tea or...my point is there's a ton to do in London, and you'll have to pick what you personally find interesting.

I'd get a London guidebook and take the time for yourself to research the things in London that most appeal to you. Combo cards like these are usually only worth it if you genuinely already want to visit all or most all of the things on the list. Wax museums and aquariums you can see in many places, while there's only one Tower of London. Many of London's museums are free admission, so a pass doesn't help you there, and other attractions allow you to purchase tickets in advance directly online. So I would lean against buying a card, but it's worth adding up the costs once you know where you want to go to see if it will save you any money.

As noted in comments, many attractions will be closed on holidays, which will influence your calculation.

If you want to go to the Warner Bros. Studio Tour for their Harry Potter attraction, their site provides information about how to get there by train, or you can scroll down to "Bus Transfers" if you want to purchase a combination ticket with a bus from London. However, as Bernhard Döbler notes, advance booking is required, and there may be no tickets left for your dates.

Long queues for tickets are not an issue at most attractions - the main delays can be for security, which you will not be able to skip even with a pass.

The hop-on tourist buses are fine if you want a tour but are not a viable means of transport on their own - they are infrequent and don't go to enough places.