I am traveling to London on 24th December and planning to spend 4-6 days there.

I am checking the tickets for the main attractions in London to purchase them in advance to avoid long queues and last minute ticket sold out problem.

I found two passes London Pass and Merlin's Magic London Pass

But I am super confused to which to choose, each have there own benefits like London pass is expensive but it includes hop on hop off but it doesn't include tickets for main attractions like London eye while Merlin's magic pass has London eye included but it has only 6 attractions.

I am super confused what to choose, I want to buy the card that includes almost all the main attractions of London where I will not have to wait in long queues and tickets.

Can anybody please guide me which are the best places and attractions that are paid and a must visit for London which I can buy in advance?

And which card should I pick and if not both then which one?

I am basically looking for some combo card where I can get access to almost all the main attraction (if it includes Harry Potter attractions what would be best)