To offer a counterpoint - I use a set of cans with no isolation at all. I prefer the broader sound stage (it feels more like an open air concert than a band in your bedroom) that the open cans offer.

I purchased a set of HIFIMan cans with planar drivers on sale for around $500, and I haven't looked back. They sound better than any other >$1000 cans I've listened to, bar none.

That said, they offer no isolation whatsoever, so you do need a quiet environment in which to use them.