Temis the Vorta said:
TOS doesn't get enough credit for being honest in the way BSG is honest. Kirk et all were often depicted as struggling to do the right thing. It was only with TNG that you got this simplistic, preachy version of Star Trek where being holier-than-thou was easy. (And I certainly hope that that version of Star Trek is gone for good.)
QFT! - If you bother to watch TOS; you'd realize that MANY times, the Federation waived the Prime Directive when a planet or culture had resources be it Dilithium Crystals (watch Fridays Child); or a strategic location (see Errand of Mercey when at first it was believed the Orgainians were just a primative people).
As stated above very well - you didn't get the simplistic/preachy version of Star Trek until TNG (and Captain Picard in particular who OFTEN seemed ready to see the Federation go down in flames rather than violated a being's 'Human Rights'(tm) - see I Borg as a prime example.