What better way?

With this sentence

What better way to celebrate the peace than with a fight?

Is "what better way to" an informal phrase? Would it be better to write

What is better than fighting as a way to celebrate the peace?

Solution 1:

What better way to celebrate the peace than with a fight?

This phrasing highlights the irony in the statement (a fight celebrates peace) by juxtaposing the words in close proximity.

"What better way" is an English idiom which is rhetorical. The question doesn't literally ask for a better way, it posits that there is no better way. I don't feel the idiom is particularly informal, I don't think you should worry about using it in formal writing.

What is better than fighting as a way to celebrate the peace?

This phrasing sounds needlessly clunky, and comes across sounding like you are seriously asking for a better means of celebrating the peace, since fighting is clearly not sufficient.

Solution 2:

In studying the phrase "What better way", I have found that it is a commonly used phrase since edwardian times in English jargon and is considered proper when followed by a validation. "What better way, than to jump in head first".