To answer the initial question of this thread, first it must be said yet again that there is no "correct" choice. Two undeniable reasons this is true: 1 because we do not know the outcome of either choice (yet); 2 each player defines what they believe "correct" is.
I want to focus on the second reason for a moment, because it is critical in the reasoning behind the paragon and renegade choices. The concept of correct is inherently dependent upon perspective, Consider this, you have a choice between rescuing one of 2 boats that are sinking. Boat A has 1 person on it, boat B has 100 people, which do you save? Most ethical codes and their instilled morality would guide you towards saving boat B. However what if the person on boat A had the cure to cancer, and if you saved them ultimately thousands could live who would otherwise die? That single piece of information has shifted perspective, no one would blame you for saving boat B if you didn't know that information, but it gets fuzzy once that twist is known. This isn't a direct comparison to saving or destroying the base, don't take it as one. Instead realize that in playing through the game we all accumulated different information, each shaping our own perspectives. Even if we all had the same information, certain parts of the story and characters appeal to each player more than others. What each of us deems as "correct" is not going to be what someone else thinks is correct, not because their reasons or our reasons are bad, but because different parts of the story mean more to us than others. Unless Bioware makes the outcomes of a particular choice cross a fundamental ideal or concept which we all view as incorrect, there are no correct choices in this game. For instance, since we are all trying to save the galaxy, Shepard choosing to sit at home and not do anything would be considered the "wrong" choice by an overwhelming majority (except by emo kids wanting to feel unique and special). Whether you make your choices based on some morality, logic, or even spur of the moment inclination, those choices are yours and as long as you chose them because you wanted that choice at that moment, they are correct.
Finally getting to the heart of the matter, Paragon and Renegade need to be defined, they are not good and evil, they are not mutually exclusive of one another nor are they even 2 sides of the same spectrum. No matter what choices you make in game, Shepard always comes out a hero does he not? You'll always repel the initial reaper invasion in ME1, and you'll always remove the collector threat in ME2. Paragon and Renegade are based on two things, one is personality or style, and the other is that focus or perspective I mentioned earlier. The best example I can give is this: Luke Skywalker is a prime example of paragon, Han Solo is a great example of renegade. Both are heroes, both are key in defeating the empire, but each of them does things their own way. Luke is brave, noble, optimistic to the point of being foolhardy. He believes he can beat anyone, do anything, and is an idealist (which ultimately works out for him as he isn't swayed to the dark side). Han on the other hand knows life isn't fair, fairy tales aren't true, and he shapes his perspective around ensuring survival/success for himself and those he cares about. He is aware of how strong the Empire is and doesn't want to just throw himself out there to get killed. Neither of these approaches are wrong, and there must be overlap between them for either to be successful, Luke would die right away if he just charged forward on ideals, and Han would have no friends/allys if he only looked out for himself and he'd ultimately die as well. This is why you can get both paragon and renegade points, playing purely paragon or renegade is unbelievable, reality is a mix of both.
So as for the decision about the reaper base, and each players perspective on what is the correct choice, let me suggest this phrasing of the question. Are you like Luke, driven by ideals, optimistic that you can beat whatever comes your way regardless of how strong it is, and your going to do it being brave and noble? Or are you more concerned with the power of the reaper threat like Han, realizing that you need every bit of help you can get to fight off their technology and numbers?
-TrueRedemption
P.S. If you actually read the whole post, grats, and my thanks, if you thought it was tldr, your loss.