Having worked at Winn Dixie for 5 years...
Publix is by far the best of the 3...it is the nicest and the cleanest...but you get what you pay for...You will find most of the same food at all 3 stores, but at Winn Dixie and especially Albertsons, you sacrifice a nicer shopping atmosphere for a lower shopping bill. After working for Winn Dixie, I usually do all my shopping at Publix...it's worth it.