I have a few some I don't think will come... or at least not the way I want them:
Farming of course! I want mostly to be able to take care of farm animals and have a more old fashioned type of farm. I'd like some crafting that would be expected for the products you get from the animals.. eggs, wool, milk. I'd also like to be able to make jam or jellies.
Dance pack to include couples dancing from club dancing (facing each other) to ballroom types of dancing waltzes, foxtrots, salsas, tango ect... The more options the better. I think the amount of animations I have in mind though are too much for one pack so at the very least a few couples slow dances and some club dances.
Bands with a singer or just to have play a variety of music together. Have multiple ways to perform classical, jazz, retro, country, rock ect... Mostly if they bring it I don't want to get stuck with only a rock band and some rock show.. I mean I'd probably play it but not as often as if I could pick what they play. Would be nice if you could get a band to play at an event like a wedding reception or in a music hall... maybe you'd have to set it up a certain way to work or they could have a band object you set out so that the sims take their places. Lots of ways this could be done.
Some sort of Beyond Death pack. It would feature going to the Grim Reapers world or areas, either as a ghost or a living person. I mostly want more interactions with Grim and ghosts. I'd like to be able to woohoo grim or have a child with him. (Let me create Nervous Subject from Sims 2 without cheats!) More depth as to what happens to ghosts and where they are when they aren't popping out of the tombstone. Aside from that it could have a quest or a way to cheat death or bargain with death if your sim recently died or drag someone back if your sim is living. (Maybe with repercussions like possible zombies). That they made the Star Wars pack and a way for us to chose to go there but limits what you experience otherwise gives me hope that we could get a pack like this with limited effect if you don't chose to engage.
Would be nice if they included a cemetery lot with more interactions free with some sort of pack that features Grim.
A romance pack... with things simmers want like an attraction system. Mostly I want bed cuddles and more interactions and that slow dance I mentioned if we don't get it another way. Maybe more structure for a wedding ceremony?
A motel pack (I know people want to run resorts but with the 20 sim limit... ehh). I'd like to go to a motel or hotel on my sim. Pay for the room, be able to keep your area private from walk ins. Maybe order room service and have maid service. I'd also like to be able to run a motel (really want to run a Bates Motel) or B&B.
A vehicle oriented pack with a free base game car update. I'd the pack to have a mechanics career, be able to build some cars, have a large variety of cars to buy and park in your sims driveway, repair cars and of course be able to woohoo in them ect... although the woohoo option should be base game update also. Other possibilities maybe... have a raceway area that you could go to? I wouldn't put too much put into that idea though I'd rather have more car options and mechanical abilities.
Lol sorry I have way more than one dream... and still want so much I haven't listed.