I have definitely had an interesting journey with this series, more than once it has been my favourite series of the time, but sadly it did not end well for me.
I first watched Bakemonogatari when it aired. I was brand new to anime, and I think this may have even been the first ever series I watched whilst airing.
I thought it was great. It was weird and different and had a host of quirky characters. It did suffer from "that" type of protagonist, but not to the point where it was unbearable. I don't need to write down all the unique qualities this series brought to anime, as anyone that has watched it knows already how it does this.
Nisemonogatari followed and some of this I hated, fan-servicey elements I seem to recall. I didn't like it in S1 either, but felt it was just bearable, now it's getting to be irritating. Other parts are great. The introduction of Kaiki, one of the best characters imo. This series felt a bit weaker, I wasn't sure of the point sometimes, but it was setting the scene for what followed so can be forgiven when looked back on as part of the whole.
Second season comes in. This was the peak of the series for me. All of the backdrop that has been set up across the previous two seasons comes to full realisation. Every character is explored, the plot is engaging, the quirkiness is still fun. Nadeko's arc stands out as particularly memorable, and Kaiki becomes a firm favourite for me (it's been 10 years so I barely remember any of it!) Ougi is introduced who is a mysterious and friendly but obvioiusly secretly evil which is exactly the sort of thing I like, so I am interested to see what she is about.
Then Tsuki comes out, and I love Ononoki, however, it is slightly wearing off. It's gone back to some of the problems I had with Nise. I undertstand that's the shtick they've gone with and what has made them popular, why change it? Perhaps it is more engaging when you understand Japanese, but some of these metaphors and language dissections are only coming across as pseudo-intellectual at this point. I always had this issue at certain times, but it's more noticeable now. Overall, I still highly rate this series, I found it very enjoyable overall and was still excited for more.
Owari comes out, and it seems like there is going to be a lot of Ougi in this season. I'm excited. I've been interested in this character for a while and I want to see what the hell happens. Well, maybe I have outgrown the series at this point, because I cannot finish it at all. I got 5 episodes in I think? I'm finding it simply absurd. Nothing they say makes sense to me. I could not care less about Sodachi and I've now put up with Araragi for so long that I'm at the end of my tether and wish he would just stay at home perving on his sisters and stop engaging with this town in any way at all. I ended up dropping the series.
I never did find out what happens with Ougi... I disliked it so much that even my strong curiosity to find that out was not enough to keep me going. It was a very sad moment for me, as I sang praises to anyone who would listen about Bakemonogatari and Second Season. I'm not 100% sure if I would love them as much as I did at the time if I were to watch them now, and for that reason, I'm going to let them live on as memories only and not revisit it.