Ever since the Orc librarian bugged out during the last fight and came out of nowhere to kill Ancano with a bare handed finish move I'm bound to love the College of Winterhold forever.
Besides this, I don't like anything else much. Maybe the Empire, I've come to like Tullius and the fact that he ended up respecting Skyrim and the Nords.
I'd have liked the Blades if Delphine wasn't a major jerk, Esbern got me to respect the faction and the history behind it. Also, I don't blame them for doubting on Paarthurnax, the dragon said it itself, they were made to dominate, and if given the chance they'd do it again, and this one may have hidden something.
I've never got along with the Thieves Guild and the Dark Brotherhood due to extensive years of games and MMO's. Anything that is mysterious, carries a hood and daggers gets a fireball. I would have prefered the Morrowind version of contract killing.