Fairy Tail isn't so much a bad anime, it's just over-welcomed it's stay. It was a one trick pony that was constantly played until you get annoyed and see the repetitive nature of the show and it's sad because this had a lot of potential to be really good .
Story - (3/10)
This is one of the weaker aspects of Fairy Tail as it gets daunting and rather boring because there is no real progression, and it becomes incredibly predictable with how it will play out, at first it was pretty fun since the stories did serve a proper purpose and introduced us to some other characters but as it goes on, you feel that it's afraid to make changes to the characters so they just write what they know and that's where the repetitiveness comes from. The gags were funny for the first 20 episodes but then they get really old fast as well as the fanservice, it even gags at important moments, you could have a serious fight but instead have a comedy bit in the middle completely ruining the mood for the fight.
Art - (6/10)
The animation is pretty good for a shounen anime as it can be fast paced and some of the magic does look pretty cool but at the same time, the designs of most characters seem really plain looking, minus maybe 2-3 characters everyone else looks really generic.
Sound - (9/10)
Quite possibly the best thing about Fairy is the sound as it mixes irish folk music with some modern day sounds blending really well and does match the battles that happen, this was something I am glad they kept as it was something very different from the norm. The OP's and ED's were also very nice to listen to and mainly composed of some very energetic pop music.
Characters - (2/10)
This is by far the worst aspect for Fairy Tail, one dimensional, bland, incredibly cliche and just lacked development. I will start off with the main character Natsu who is to me one of the worst MC's in anime ever. He never develops, there is no challenge for him, he doesn't have any conflicts with how he does things its just 'I'll beat the crap out of you' no matter how evil that person is, even if they kill someone he will still treat it more like a sparring match rather than him losing control and losing himself in the process of it, if he's always going to be this guy who doesn't think and just swings away then its going to get really boring really fast.He doesn't so much get stronger but rather uses the power of friendship after making a speech and wins. Lucy is another character I just could not handle because she was just fanservice and a plot device, she didn't get stronger each time, she just gets caught in a messy situation, screams a bit, summons a spirit and that's it, her character seems to be a key for the arc to go through but apart from that she is utterly useless. Now despite all the bashing of the characters I will say that there are some decent characters like Erza, Wendy, Gajeel and Gray because most of them did get stronger and developed and were conflicted with how they did things but even they can fall victim to lousy progression.
Enjoyment - (4/10)
It was fun at first but once the story and comedy repeated all the time, you get sick of it and switch to something else straight away, there is no proper pacing and some arcs went for too long that you don't feel as invested or interested any more to care
Overall - (3/10)
Fairy Tail lacked a lot of important elements and was clearly confused as to what it wanted to be, it was either over the top battle or a comedy, it was too messy to balance both because it couldn't have the comedy at the right time, I wouldn't recommend this anime because it's fallen to the many cliches and doesn't really bring anything solid to the table.