The new 64 bit engine should make the game more stable. But some mistakes from the reference game are still there.
So, to start the mod mania, there are a few essentials you should always grab.
1. USSEP The community patch
2. Brumbeks SMIM to make all objects more appealing and fix some nasty graphics glitches.
Than there are a lot of mods that improve game play, characters and a lot more.
Here a top 5 for now:
1. Ordinator (Perk Tree Overhaul)
Makes the game a lot more fun to play with some more useful perks and some crazy ones as well.
http://www.nexusmods.com/skyrimspeciale ... mods/1137/?
2. Wet and Cold
3. Ars Metallica
Greatly improves smithing. Melt down stuff to create armors etc.
4. Immersive Citizens Overhaul
Makes the daily activities of NPC more interesting.
5. The Paarthurnax Dilemma
Removes the need to kill the master of the voice on top of the Throat of the World to become full member of the Blades.
And then there are the "run for your lives" and "when vampires attack mods" that will save citizens, so the game does not turn into a ghost town quickly. Always found it ridiculous that a lady in a dress with only a dagger attacks a Dragon
Things like that will be fixed with these mods. People will take cover or gather at the inns during attacks.
http://www.nexusmods.com/skyrimspeciale ... mods/2272/?
http://www.nexusmods.com/skyrimspeciale ... mods/2275/?
There are also a lot of options to improve the looks of characters in the game. That is more of personal taste.
I'm still modding the game and have not played it yet
I will most likely start the game without very heavy weather modding.
But a good weather mod is Vivid Weathers.
http://www.nexusmods.com/skyrimspeciale ... mods/2187/?