Central Market would definitely make my list of the top 5 things I would miss if I left Austin.
CM excels at making grocery shopping an enjoyable and educational outing rather than a weekly chore. I always try to leave plenty of time to wander the departments and try the cooking samples and check out all the fresh foods to inspire the week's recipes.
What's great is that Central Market isn't really even more expensive than HEB or your regular grocery store and we usually SAVE money due to the fact that we can buy just the amount of herbs/grains/spices we need, like a small 5¢ baggy of curry powder or $1 worth of sugar. And the regular grocery section, while focused on Organics and natural foods, does carry enough national brands and "regular" foods that you won't need to make another trip to a traditional grocery store.
The staff is friendly as hell and very helpful when you ask their advice. The seafood guys routinely throw in some disposable gloves so my girlfriend can devein the shrimp. And once when having a wine party, the wine staff recognized our invitations in the guests hands while shopping and recommended different wines for people to bring that evening!
I'm also conviced the coffee is among the best in Austin (I can never seem to replicate the magical ratio they have in their sampler coffee pots) with selection that's unmatched anywhere else in town.
What's more, the cafe is icing on the whole deal... Great tasty food and we'll routinely eat dinner there before shopping so we don't buy the store on an empty stomach.
Even though I can walk to the new flashy Whole Foods downtown and buy $6 tomatoes, I'll make the extra effort to go to CM for the week's shopping. It's selection is more mainstream, the staff down to earth, and the prices more in line with my five-figure income.