I miss:
Visitors allowed lots
Edit town
Placing lots in unusual places, such as on cliff tops, on the beach, or anywhere around the world in general
Being able to build whatever kind of lot I wanted with objects that townies would use, such as a fishing park, a swimming pool, a lodge near the waterfall, a hotel, cafe or guest house, etc
CASt and being able to recolour clothes and build/buy objects (I REALLY miss this!)
Watching and arranging sims to meet up at the bistro, town hall, beach, restaurant or the cinema and actually spend time together without wandering off
Cars and bicycles, garage doors and driveways
Self employment
The consignment store
The cemetery
Visiting other sims houses without a loading screen
Taking a gardening, handyman or cookery course
Seeing sims sitting outside the bookstore waiting for my sims to chat to
Buying property in town and making simoleans from it
My sims running around the countryside at night
Pushing a pushchair down the road
Babies that were not tied to a crib
Terrain tool
Postman, paperboy (I don't miss the burglar!)
Sims dancing together
Sims reading a book and actually keep reading it for as long as I request them to
The school and the school bus and seeing children walk into school
Taking a sim to meet another sim from work
Being able to switch from one sim to another no matter where they are in the world simply by skimming across the landscape
There are many other things that haven't come to immediately to mind but I'm sure I will think of more as soon as I post this comment!
Edit: Oh yes, perhaps a little unpopular but I miss the rabbit holes (more especially the modded rabbit hole mats and/or doors which allowed me to build my own building but with the rabbit hole functionality) I loved the ambience of the music which came from the bistro and diner.
