I am not going to talk about many of the virtues and the flaws that have been stated in the apparently irreconcilable fight between those that love this anime and those that hate it. I just wanna say, to those that want to enjoy a show and understand it's relevance in the anime community but seem kinda lost in the debate between fanboys and haters, that this show is practically for everyone but not for every moment or context. And it is an advice that can apply to any serie actually. I don't know what weird subconscious cognitive stuff is behind it, but if you watch the show (hopefully in the broadcasting order -starting with Bakemonogatari-) and don't like it at first, please don't force yourself! If you do you will end up hating it and complaining about the "weird fan service", the "cheap animation" or the "word porn" (to use some misleading terms I have read in many negative reviews). I mean, It may be cool to say "this is crap", and accuse anyone that likes te show to be a weirdo, but come on! I personally want to experience the same emotion and enjoyment that others seem to live. It's true, sometimes it is not possible because the anime is just bad (like who knows, Mars of Destruction), but this is not the case with many animes and it is definitely not the case with the Monogatari series.
So, if you want to enjoy this franchise, just prepare yourself for something different! I can promise you that if you approach this anime when you fill like it and being opened minded, you will discover a very interesting and intriguing story, a lot of characters with great developments and excellent interactions and in my opinion a masterpiece concerning art and music. In the end, a truly enjoyable experience...
Objectively, I would give to Owarimonogatari a 9... but because it represents the series that made me realize that my subconscious and other things may trick me sometimes and stop me from enjoying a truly wonderful show, well, here is the 10!
Hope this was useful!
