What is your favorite Sims 3 EP/SP?

Sims 3 had so many good expansions and stuff packs that it's hard to choose just one.
But I like playing family style. So, I get a lot of use out of Generations, Seasons, Pets, and Ambitions. I actually use almost all of the expansions pretty regularly.
For Stuff Packs, I think Diesel and Master Suite has some really nice clothing and I use them very often. Outdoor Living has some nice furniture, which I use a lot.

My current favorite is world adventures. I love exploring the tombs and I'm a goal orientated played so I like having the adventure quests to follow.

I always had a softspot for Late Night, a nice big Sims 2 styled Downtown you could live in, the classic vampires, and easily houses some of my favourite premades from 3 bar Island Paridise. Everyone there has extremely memorable faces, the penthouses are a fun idea, even if they're somewhat downgraded TS2 apartments, and even if the city lags beyond belief even with fixes I've found more to do there than I've ever done anywhere else. Although I'm not really a family player so I found it easier to keep getting my Sims out to venues.

I'd say my favourite stuff pack is Full Fart (Norwegian for Fast Lane) by name alone... Also cars, I love cars. I would've put High End loftstuff here because it had the Heart Bed from TS1, but Fast Lane/FullFart wins just for the sheer amount of cars.

My favorite pack is Supernatural with the Moonlight Falls world, Lunar Moon, Fairies & Werewolves.

I'm pretty biased for Seasons. That's just something I always seem to enjoy. In general, I favor packs which augment the core gameplay and don't require me to, for example, go to a specific location to get something out of it. (One reason why Generations is my next favorite.)
Weather affects everything in day-to-day basis and has such a major part to play in immersion and overall enjoyment. Plus I personally love listening to the weather effects, especially rain, so playing the game with Seasons enabled has this sort of relaxing effect on me. I'm one of those weirdos who will go walking outside with an umbrella when there's a refreshing summer rain. (Though if it's light rain I sometimes go jogging without any protection. That weather just feels so fresh for your lungs so it feels like I do my best performances then lol.)

Supernatural, I love to mess around with the potions and the alchemy skill. The full moon atmosphere is really nicely spooky. And the music is *chef kiss*.

Pets is my fav EP coz of horses and my SP has to be fast lane for the cars lol ?

It changes all the time. I’m currently loving the nightlife/downtown/party lifestyle, so Late Night is my current favorite EP.

And for SP, this may be unpopular but I really like 70s, 80s, and 90s.

@Astro I actually really like that one too, I just wish it came with a few more outfits and such