Unsweetened almond milk and oat milk are perfect - the after taste is so much nicer than regular milk.
Is you can find it where you live, Oatly Barista is delicious. A bit rich on its own, it can be watered down a touch. Doesn't curdle in coffee.
I switched to oat milk because the environment impact of almond milk was a deterrent. Oats are a native crop in the western hemisphere so the food miles to here in the UK are lower than for almonds, which are predominantly grown in drought ridden California.