1. Choosing at the start one out of three maps, i don't want to start again and again to find a good town
2. Catching reptiles (with the net) and birds (with special traps or baits or something)
3. A camera as a new tool, so you can take photos in the 1st person perspective
4. More characteristics, maybe combining so the villagers getting more individuality
5. More species for the villagers (reptiles, racoons, owls, flamingos, hedgehogs,skunks and so on)
6. More flowers (and hybrids), fishes, bugs, gyroids, festivals (all from gc, ds and wii-version and new), shells, fruits (adding nuts and berries), fossils
7. Open nook 24 hours, maybe get a new worker for the night duty or take the idea from animal crossing e+
8. bring back igloos and tents
9. mini-games with the objects (eg billard)
10. Add temperaturs, wind, fog, thunderstorm
11. A garden as expansion for your home
12. arrange color palettes on your own
13. more town decorations (windmill, lighthous, fountain, graveyard, something stone henge like, a very big epic tree, a reed-pond, a cruel withered tree (bigger than the other ponds) and so on) not all in one town but to choose when you spend money
14. buying sculptures from redd to spend to the museum
15. befriend with villagers so they treat you friendlier, or be hostile to someone so the villagers sayings are more individual
16. Having more towns/savegames (like in gc-version with two memorycards) so you can visit another city even if you don't have wifi or friends who are playing ac too
17. before a new villager moves to your town you can see on the bulletin where the villager places his home. Then you can remove the flowers and they don't disappear
18. new shops in the city, like a flowerstore(a butterfly is working here, you can buy flowers, grass-seeds, saplings), perfumery(a skunk-lady as seller, perfume will appear like a transparent colored cloud), apothecary shop (a snake-seller, you can buy mosquito repellent spray, ointmet, the medicin you getting now at nooks)
19. stinging nettle as new weeds somehow like clovers, if you run threw them or pick them up your skin is getting itchy and you need the special salve from the apothecary shop otherwise your character will stop often to scratch himself. In the flowerstore or at nooks you can buy gloves (a new „tool“) to prevent this
20. when you fall (pharao mask, trap) you get a graze and need the ointment from apothecary shop
21. you should be able to change the background music, there are a few melodys you can choose at the telephone in your house
22. adding new sayings for the villagers like dlccontent, so it will never get boring to speak with them and they don't repeat to often
23. A cave in the town where you can find mineralstone and stuff like that that you can spend for the museum. its like the underground from pokemon diamond/pearl
if you don't know it here' a description
http://www.serebii.net/diamondpearl/underground.shtml
i hope you can understand what i'm meaning in these points, i don't speak english so there are certainly a few things that are not very good explained..