Formal:
* moltissimo (most) - This is the most common and formal way to say "very much."
* molto (much) - This is also quite common and a little less formal than "moltissimo."
* estremamente (extremely) - This is a more formal and emphatic way to say "very much."
Informal:
* tanto (so much) - This is a very common and informal way to say "very much."
* un sacco (a lot) - This is a more informal and colloquial way to say "very much."
* un botto (a ton) - This is a very informal and slang term for "very much."
Other variations:
* molto di più (much more) - This is used to emphasize that something is much greater than something else.
* affatto (at all) - This can be used to express a strong emphasis on the intensity of something.
* davvero (really) - This emphasizes the truthfulness of something, implying that it is indeed "very much" so.
Example sentences:
* Grazie mille! (Thank you very much!)
* Mi piace molto. (I like it very much.)
* Sono molto felice. (I am very happy.)
* Lo voglio tanto. (I want it very much.)
The best way to choose the right phrase depends on the context and the level of formality.