How to choose the best:
Cucumber

AKA: KIRBY

Touch

First and foremost, look for firm cukes without any soft spots, which can be signs of rotting.

See

Look out for any yellow or brown spots, and while a couple of scuffs are alright, look out for cucumbers with too many blemishes on the outside.

Some more details:

When it's in season

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec.

FYI: for this Vegetable, its best to buy organic.