Good, better, best in Spanish

Regular (mas, menos)
To regular way to express comparative and superlative in Spanish, mas or menos is used. They don't change with male or female.
rico	más rico	el más rico
tasty	tastier	tastiest
	menos rico	el menos rico
	less tasty	least tasty
fresca	más fresca	la más fresca
fresh	fresher	freshest
	menos fresca	la menos fresca
	less fresh	least fresh
barato	más barato	el más barato
cheap	cheaper	cheapest

Irregular (mejor, mayor, menor, peor)
In the irregular form we use mejor, mayor, menor, peor. These can have several meanings. Grande → mayor (big, bigger). Viejo → mayor (old, older). They don't change with male or female. *
bueno	mejor	el mejor
buena	mejor *	la mejor *
good	better	the best

malo	peor	el/la peor
bad	worse	the worst

grande	mayor	el/la mayor
big	bigger	the biggest

pequeño	menor	el/la menor
small	smaller	the smallest

joven	menor	el/la menor
young	younger	the youngest

viejo	mayor	el/la mayor
old	older	the oldest

Tú más alto que yo
You are taller than me
Pedro el chico más inteligente de la clase
Pedro is the smartest boy in the class
Este libro bueno
This is a good book
Ese libro mejor
That book is better
Aquel libro el mejor
That book over there is the best
Pedro menor que Carmen
Pedro is younger than Carmen
Carmen la mayor de la familia
Carmen is the eldest of the family
El agua de mayor importancia que la comida
Water is more important than food
La comida de menor importancia que el agua
Food is less important than water
La niña joven, el niño menor
The girl is young, the boy is younger
La abuela vieja, el abuelo mayor.
The grandmother is old, the grandfather is older

Conjugate Spanish verb