What is the #1 Gardening Tool for the Serious Landscaper?

If landscape maintenance is your career or past time......I suggest there is only one gardening tool for your tool belt. Felco Pruners with a Felco Holster should be part of your attire.
There are tons of pruning tools on the market. They range in size and color. While speaking of color,

A tip: Choose the brightest handles. As a landscaper and avid gardener, bright red is easy to find if I should drop them or lay them down somewhere. Habitually using the Felco Holster is a better practice.