I personally really like Punt e Mes and Negronis twisted with it, but beware that is the most bitter among Italian (sweet) vermouth, because it has an higher cinchona % in its recipe (literally punt e mes in milanese dialect means 1.5, which refers to the 1.5 level of bitterness compared to 1 as standard of any other sweet vermouth).
If you like a more bitter negroni, just go for it, I love it.
If you want something more classical, Carpano Antica Formula it's great, I agree, but Carpano Classico it's a solid choice for a negroni, I probably prefer it over Antica Formula. Antica Formula it's sweeter, it has a strong vanilla note, while Classico it's more balanced with a citrus note, which goes great with gin.
Another option I really rate it's Cocchi Vermouth di Torino. From Cocchi you could also find Cocchi Dopo Teatro, which is more bitter, similar in a way to Punt e Mes.
Last but not least, Martini Rubino Riserva Speciale does its job extremely well in a Negroni.
If you like a more bitter negroni, just go for it, I love it.
If you want something more classical, Carpano Antica Formula it's great, I agree, but Carpano Classico it's a solid choice for a negroni, I probably prefer it over Antica Formula. Antica Formula it's sweeter, it has a strong vanilla note, while Classico it's more balanced with a citrus note, which goes great with gin.
Another option I really rate it's Cocchi Vermouth di Torino. From Cocchi you could also find Cocchi Dopo Teatro, which is more bitter, similar in a way to Punt e Mes.
Last but not least, Martini Rubino Riserva Speciale does its job extremely well in a Negroni.