Wines to age for 20+ years

jfuruno thought this was worth mentioning said

I’m pondering a project to put some bottles away to give to or enjoy with my daughters many years down the road. Looking for bottles that are ideally somewhat affordable now (~$50 or less), but with a high probability of being special in 20 years. Also, would love to focus on wines from their birth years (2015 and 2017).

Anyone have any suggestions for varietals and specific bottles? I know to focus on cabs, nebbiolo, barolo, maybe champagne, but would welcome any suggestions on this.