Hey, thanks for the question!

As an all-rounder, I’d suggest Southern Weather. It is Onyx’s batch brew option in all cafes, but can also be used as an espresso (all of their blends can be).

Monarch is their darker option and the default for all of Onyx’s espresso-based drinks 8oz or larger because it does so well with milk.

Geometry is (I believe) used for smaller espresso-based drinks with less milk (<8oz) because of it’s more delicate flavor profile and lighter roast. I’ve enjoyed Monarch (classic, full-bodied) and Geometry (lighter, more tea-like) as espresso.

Tropical Weather and Geometry are both really good and lighter roasts. These tend to be my favorites of their blends for drip-style coffee.

Honestly, you can’t go wrong and I think you’ll like all of them. If I could pick two, I’d suggest Monarch for espresso and Tropical Weather for drip. Let me know what you decide and your opinion when you’ve tried them!