My hands-down favorite brand
Blue Sky has some of the most intuitive planners on the market. They offer multiple ways to organize and cross-reference your calendar obligations and don’t restrict you to using up pre-organized time sections. I like being able to provide levels of information, depending on the event. The cover and binding is sturdy enough to survive my commutes, and the full-size pages make it easy to tuck loose papers into to copy information from later.