It really doesn't effect gameplay much and of course, Skyrim is a fantastic game without it, but I very much miss the ranks on factions like there was in Oblivion. And I mean with their own little picture and menu so you can see what your character has accomplished.

What do you guys miss?

I miss detailed quest logs. Would be nice to be able to turn off quest markers and have something to go by instead of all this hand-holding.

I didn't notice the ranks in Oblivion. They were mostly useless. But in Morrowind they actually have purpose. I miss them too.

I miss the faction structure of previous games too.

This I agree. Ranks in morrowind were nice.

I miss how each major city was big enough to have their own guilds/knightly orders.

Ooh, I like those. Especially the pretty pictures that came with the ranks. But rank in Skyrim is much looser. One minute you're a student, the next you're the archmage. A shame. It makes sense for some factions, I suppose.

you can turn off the floating markers,which is nice

That was main concern since the first news about Skyrim. But still, it turned out to be that quests are designed with markers in mind. It is simpler to just make a magical arrow than to write down some sentences for voice actors to speak out. Radiant system with it's randomness also played its part.

Yes, it gave a sense of sprawling guild present in province. In skyrim it is now in one place, for some people to not get lost, i guess. Here's your streamlining, and don't bother convincing me that this is because of the lore, because the lore gets changed accordingly to the game they are making.

sadly the TES series seemed to get more simple every series.

This

While it was sweet, the faction titles and pictures was just fluff, having no purpose other than as eye candy.
At worst it was immersion breaking since it clearly showed that it is a game.
I don't miss them at all.
The best example of how it was done well was in my opinion Shivering Isles.
Bear in mind that the Fighters Guild and Mages Guild were Imperial, legal, sanctioned and had a ranking system and hierarchy.
I much prefer the more relaxed and informal style of the Companions or the Stormcloaks.

I don't miss the quest logs from Morrowind and Oblivion, especially Morrowind.
Prepatch it was a mess, post patch it was a still a mess but not as much, especially trying to find what you need in the inconsequentional verbiage.
Oblivion, didn't like it.
I much prefer Skyrims quest journal system,
A lot less frills and easier to use and find what info you seek.

I'm playing Morrowind and Vampire the Masquerade Bloodlines and the lack of quest markers and fast travel really hampers the experience.
Especially in Morrowind, finding a specific eggmine or place was a test of patience and frustration, everything looking too samey, all greens and browns or grey and black in the ashlands.
The ingame journal and NPC directions didn't help most of the time and were sometimes wrong and following them leads to a completely opposite direction.
It didn't help that the ingame minimap in Morrowind was poorly detailed, didn't have height scaling and was overall badly and inefficiently done.
Not much help at all.

Doing one of the many quests in Skyrim that DOESN'T have quest marker arrows only serves to remind me how frustrating it can be.
The Destruction and Illusion ritual spells being the ones i do the most frequently.

Funny, thats one of the things I love about Morrowind, although id use more positive adjectives like challenging and immersive.