Final answer:
Neutrophils are the most common leukocytes, while basophils are the least common.
Step-by-step explanation:
The most common leukocyte is the neutrophil as it normally comprises 50-70% of total leukocyte count. Neutrophils are larger than erythrocytes, have a lobed nucleus, and their granules stain light lilac with chemically neutral stains. On the other hand, the basophil is the least common leukocyte, making up less than 1% of the total leukocyte count. Basophils are slightly smaller than neutrophils and eosinophils, have large granules that stain dark blue, and a two-lobed nucleus.