Well, the English language did steal a bunch of French vocabulary....

And all the French names!

Thought about this.

Taking into account that mods exist for a lot of things (most of them I don't actually use, so...)

And that there are great custom content creators out there

I will settle for:

Less building restrictions (but then, nobody would ooh and aah about the magnificent builds by Zarathurstra and SimsArch (and some others too)

A stuff pack with nice clothing for elders - but then, they are catered for by amazing custom content creators

More things to do in vacation hoods - Now, that would be nice.
The surf mod is cool, though. And if you add a number of simple community lots, like restaurants, clubs, a swimming pool, an art gallery, a skating rink - things often found in local vacation towns here - it gives sims who are too busy to go out often a chance to have some other experiences.
I would like them to be able to fish in the ocean without the object mod - half of the fun fishing is asking others to join after all.

I like fishing with friends, as long as I don't catch anything.
Once I did catch a fish and I panicked immediately. The fish went back to the sea and I went to a tavern to recuperate.

Fine, the tavern is fun too

TS4 doesn't even have cars.

Those boats are brilliant, thanks. If someone can make it so more than one sim can go boating and make it so they can stop anywhere to just sit and talk, then it would be perfect.

"Stuff" like CAS content and plain furniture without any new features can easily be done through CC, so when it comes to what a team working on the game should be adding, I'm always thinking in the direction of how to add new features, new animations, new coding, new possibilities into the game.

There's plenty of "stuff" if you go looking. There's not as many new features, because there's less to work with.

I'd love some sort of "Features" pack where it added a bunch of entirely new things (that modders and CC-makers could build on to make even more fun stuff). I don't care if it wasn't even themed, just filled with good and useful semi-random items.

A lot of these exist as modded items already, but if their animations/coding were integrated into the game, they could probably be more expanded on than they currently can, and the functionality would be much better - usable kitchen appliances (waffle irons, ice cream machines, etc.), travel equipment (boats, bikes, car seats, baby carriers, etc.), horses and other animals (riding, farm animals, birds outside cages, various small animals outside, etc.), Bunk beds, toddler beds, more things to do with toddlers/infants, more toys with different functionality... and so on. The list is long.

(I actually do like a lot of the features TS3 and TS4 has to offer - the ideas, anyway. The execution of the ideas, not always as much. Mostly down to repetitiveness and lazy handling, especially when the packs pile up, the updates break, and the spaghetti-tower code goes bonkers).

Hmm. Dream Expansion . . .

A Rural Living Expansion, like the Apartment Life Expansion and Downtown Expansion together make for city living.

Yes, we have modders who have made ridable horses and milkable cows and hunting and wild berries and canning and . . . you know, ordinary life stuff, and we can put together the equivalent in custom content and mods, more or less. But that would've been an excellent expansion pack, with all the animations and everything. They could have had a Fair, where Sims could enter competitions and go on rides and eat at new food stands and buy souvenirs, for a new kind of subhood for the pack. It could draw on the Seasons gardens and the Freetime crafts.

(Yes, I probably should be picking sour cherries and chokecherries, but I'm also baking granola and bread, so that's my excuse for playing with the computer midday, and also it's hot out, and I'd rather pick in two hours when it's cooler)