For me, Monogatari Second Season (aka Season 3) has done a great job of rescuing the series and removing the bad taste left by Nisemonogatari (Not everyone hates it, but most would admit it is the weakest material by far when compared to the rest).

I liked how the arcs shown were not done in chronological order and that we had different narrators for most of the arcs. Seeing events unfold from other characters' perspectives kept things interesting. Most of the arcs were very good, I wasn't as big a fan for Nadeko's arc but that has more to do with not really liking the character than what happened.

This second season has restored my faith in the series and I am really looking forward to SHAFT animating the remaining material now.

I agree with ManiacB:
The first season is fun to watch. Adapted from novels they did a good job to keep the talking heads interesting. This means lots of weird angles, different art styles, live action sequences and usage of colored text cards (appearing for split seconds only). By the time we get to the second season the direction changes for the show. The flashing text cards only appear occasionally and the direction is rather tame. The pace of the arcs slows down and were left with TONS of fanservice (in dialogue and visuals). It is already present in the first season but it's better mixed in so it's bearable. Every female poses like a slut, a loli vampire bathing with the MC and it doesn't stop at his sisters. Much of it also feels like a dating sim: there is hardly any interaction between the girls and they only appear alone in scenes with the MC. It also hurts the supernatural side of the story, there is hardly an tension built up. Thankfully the Nekomonogatari (Black) arc feels more like the first season but is not that exciting because it is a prequel and the events during "Golden Week" already happend once in the first season.

Since SHAFT will probably animate all the "Monogatari" there will be ten or so more to come so I hope they can keep the level of the first or this will be a painful experience.

Bakemonogatari = 8
Nisemonogatari = 5
Nekomonogatari (Black) = 7

Everything about this show is amazing

I had rushed through the Monogatari series (bad idea) and honestly I didn't like it. Although, I decided to rewatch and give the series a second try after impulse buying one of the light novels and I must say, I'm in love. The Monogatari series has become my favourite anime/show of all time. It's uniqueness just draws me in every episode with characters and the world they live in. The visuals are STUNNING and the OPs and EDs are so catchy which is a huge bonus. Such an interesting anime, which if you're like me, you must watch slowly. Nothing has impacted me this hugely and I can't wait to get in the light novels :)

My order of watching and my ratings:
Bakemonogatari (10/10)
Kizumonogatari: 3 movies (9/10)
Nisemonogatari (8/10)
Nekomonogatari: Black (9/10)
Monogatari Series: Second Season (10/10)
Hanamonogatari (9/10)
Tsukimonogatari (9/10)
Owarimonogatari season 1 (9/10)
Koyomimonogatari (8/10)
Owarimonogatari season 2 (9/10)
Zoku Owarimonogatari (9/10)

Have to say that there really is lots and lots of fanservice in this anime. I never knew about it until this show -- but I am fairly new to anime.
I liked the Monogatari Second Season, Nekomonogatari Kuro and the Hanamonogatari series most!
Right now I'm watching Tsukimonogatari (seen 2 out of 4), but I don't think I'll like it as much.

The Artwork of the whole series blows me away every time I watch it. As a graphic designer I's have to say that a massive amount of time was spent on some of the backgrounds and typography.