The original Mobile Suit Gundam - often known as Gundam 0079 to avoid confusion with later installments - is a clearly flawed work. However, it is a highly impressive and progressive work given its age, and we owe a lot of what makes anime great today to its existence.
Of course, being highly influential doesn't excuse its flaws. The most obvious is its terrible animation, which isn't a case of it aging badly - it was made on a shoestring budget, and the animation was very bad even for its time. This is forgivable, as a great story doesn't necessarily need good animation to thrive (although the mobile suit designs aren't as good as later Gundam titles). Its biggest problem, however, is one that it shares with every single Gundam TV series that I have seen so far: it is very badly paced. Gundam 0079 is 43 episodes long, but for all the events of substance in it, it could easily have been cut down to as little as 26 without losing anything important. As a result, there are several stretches of episodes that drag on tediously and can be a chore to get through.
In spite of these flaws, though, Gundam 0079 is still an impressive anime, one of the best installments of the Gundam franchise that I have seen so far, and has aged better than any other 70s anime I've seen.
The best thing about Gundam 0079 is how believable its conflict is. Rather than the cliché of good vs. evil, neither army can truly be argued to be either. The Earth Federation are the ones defending themselves against the invading Zeons, but with their constant injustices towards Spacenoids, they pretty much had it coming. However, the extremist actions of Zeon and the resulting immense body count can hardly be called "just", in spite of their good intentions (and the Titans of the subsequent Zeta Gundam only prove further how, despite our protagonists fighting on their side, The Earth Federation is not good).
Similarly, there is an impressive balance of respectable soldiers and complete assholes on either side - most of the Earth Federation are merely incompetent, or not in a position to help, rather than being malicious. On the flipside, most of the Zabi family are surprisingly believable antagonists, and save for Gihren every single one of them is shown to be a multi-dimensional character, even if few of them get a chance to explore that any further. That and Ramba Ral, perhaps the epitome of Gundam's frequent "friendly enemy" characters.
Our protagonists, the crew of the White Base, don't really fit into either category, as most of them are teenagers who, for reasons outside of their control, are forced to fight in a war that is beyond their control. As a result, they make a good neutral party who fight in the war on the side of the Earth Federation, but without representing the Federation's poor and/or amoral choices. Amongst them is our protagonist, Amuro Ray, whose frequent whining can be annoying - but given the circumstances, it's hard to blame him.
Of course, the standout character is the masked Char Aznable, Amuro's rival, a character so iconic that every single Gundam series since has either featured him, or had a character who is strikingly similar to one of his many iterations. As a parallel to Amuro, he isn't really on board with his army's goal either - while he is anti-Federation, Char has a number of secret objectives that he intends to carry out over the series. Figuring out just exactly who Char is and what it is he's trying to do is the most interesting part of the series' story.
The only particularly questionable part of the story itself is the introduction of Newtypes, the series' only supernatural element - essentially, minor ESP developed out of adaptation to being raised in an outer-space environment. It wasn't foreshadowed as much as it ought to have been, and feels out of place in an otherwise realistic series.
Nonetheless, it's impressive that a show from the 70s managed to feature a war without feeling the need to dumb it down for the viewers, and as such it is quite ahead of its time. It's unfortunate that some of the later installments felt the need to take the focus away from the war aspects and focus on godawful character drama instead.
Final Words: More "important" than it is "good", but it is good nonetheless.
Story/Plot: 7/10
Characters: 8/10
Animation/Art: 2/10
Music: 7/10
Acting (dub): 7/10
Overall: 7/10
For Fans Of: Legend of the Galactic Heroes, Eureka Seven