For a good Blue Cheese dressing, try Lighthouse if you can find it. Publix carries it in the refridgerated section of the produce department.
Best I've ever had, especially for veggie dip.
Home made mayonnaise (an egg, a little bit of lemon juice, mustard, ACV, salt, pepper and a cup of Greek EVOO). You end up with green mayonnaise that tastes nothing like whatever you can get in the stores.
My all time favorite salad dressing was when I used to work for a big company that had a really cool executive chef. He saw me making a salad in the employee cafeteria once and pulled me aside and said don't eat this salad. I saw them washing it and didn't like what I saw. Stop by my kitchen and pick one up. Every day he made fresh dressing. I liked it so much he gave me the recipe and I make it at home from time to time. It's canola oil and Dijon mustard blended together.
Dude made me salad every day for like eight years. Every salad I've had since has paled in comparison.