Unable to become Thane of Riften, even after 1.4 patch (the patch claimed to fix some related issue)... I know many have run into this glitch, but I haven't seen it described in this thread. In my game, I completed the civil war storyline on the side of the Imperials and was able to purchase Honeyside from Hemming Black-Briar right afterward. I purchased the house and all upgrades, visited it to see what it looked like, then returned to Mistveil Keep and spoke to Jarl Maven Black-Briar. From this point on I lost all dialogue options with the Jarl. She wouldn't talk to me about becoming Thane.

For what it's worth, I've only played Skyrim 1.4 on the XBox (I purchased the game after the patch was out and updated the game before I created any save files).
Otherwise, I've been lucky in my game, and haven't had any truly disrupting glitches. However, here are some other things that clearly still have issues:
-"Investigate the Boethiah cultist" miscellaneous quest remains in inventory even after Boethia's Calling is completed
-Can't "Report Leifnar's death to his family" (I found the body before I talked to his family)
-Esbern asked me to "Kill the dragon located at Dragontooth Crater" after completing the Blades quests, but I discovered the location and a dragon (which I killed) beforehand and now can't seem to finish his request
-Can't "Bring a Dragon Scale and a Dragon Bone to Esbern" after completing the Blades quests
-Louis Letrush is funky and typically lurks with half of his body below the surface. In my friend's game (on another console), Letrush was self-replicating and appeared in a number of places at once!
-Has anyone else run into the glitch where you walk into a shop and there's a fountain of blood squirting out into the air in the middle of the room? This happened to me at one point during the Dark Brotherhood missions (in any indoor location I went into), but it went away after I reloaded my game.
-I once ran into an invisible dragon. He was on my radar but couldn't be seen. I aimed in its general direction and eventually struck a fatal blow, upon which point I absorbed a soul from the faintest outline of a dragon. It took me a long time to down that thing since all I had to go by was where it was on the x-axis.