Can drinking caffeine, alcohol and other diuretics be part of a good drinking regime? Tea, Coffee, Beer, Coke etc… I wonder if the benefit from amount of fluid we get from them is bigger or smaller then the handicap of dehydration. In other words it is worth to drink them if we want to have a good drinking regime? Opening on the recommendation from this question.

A PlOS One study notes drinking moderate amounts of coffee (aka moderate caffeine intake) doesn't necessarily lead to dehydration. They note coffee has hydrating qualities akin to water. Further empirical studies found no substantial fluid loss in caffeinated beverages.

EDIT: Make note we're talking normal doses and moderate intake, though source 2 goes into diminishing effect of caffeine-mediated fluid loss in heavy/prolonged uptake.

The issue therein is with alcohol, which tends to inhibit vasopressin and the kidneys are constantly permeable to fluids.