Just wondering ... which of the following is used?

[1] I've got to hand it to you!

[2] I'll hand it to you!

[3] I must hand it to you!

[4] I have to hand it to you!

Best wishes,

All the sentences are correct.
They are if you are literally handing (passing) something to someone.

The phrase 'I've got to hand it to you' also means 'I've got to recognise you've done well/I've got to acknowledge what you've done' and has no connection to physically passing something to someone. In this case, this is the only acceptable form.
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All sentences are correct.

But of course depending on your motive on passing the thing. Whether you must/have to/want to ..etc hand it to the person.
Shame on me. Of course, by them I meant 'you are so great I can't beat you in that.' I should have mentioned that. I oftentimes hear people say "I'll hand it to you" and all that, but the fact I feel I hear "I gotta hand it to you" most prompted me to ask here.

Many thanks, all.

Well, I would prefer:

I will hand it over to you.
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Please see Nona's post.

When you want to give someone credit, then "I've got to hand it to you" is the only version that is correct.

(Note: One meaning of when you hand something "over" is to transfer responsibility for something. I'll work on the first part of the project, and then I will hand it over to Jim. )

I have to hand it to you