I find the Greenway Station Shopping Center to be a nice retreat from the Towne Malls where I often feel claustrophobic breathing in recycled air, dodging oncoming traffic, and avoiding all the kiosk vendors...blech! Conversely, Greenway is never over-crowded, parking is easy to find, and during the spring/summer seasons you can get your daily dose of vitamin D while you shop.
The selection of shops is much smaller, yes, but the Center also houses the higher-end, but still commercial, boutiques that you can't find elsewhere in Madison (e.g. White House Black Market - one of my favorite boutique shops from back home).
Solo shopping at Greenway is definitely one of my favorite ways to spend a sunny Sunday afternoon. :)