I'm a big admirer of the Dutch design studio Experimental Jetset. They've had a significant influence on my personal work. The small studio consists of designers Marieke Stolk, Erwin Brinkers, and Danny van den Dungen, and they're well-known for primarily using Helvetica and producing work in the International Style. A lot of their work is included in the MoMA's permanent collection. My personal favorite is the identity system they designed for the Whitney Museum.