Without doubt...Roasted garlic and pea soup.....check out Nigel Slater's recipe. A little bit time-consuming in preparation, but well worth it.
Also a Nigella Lawson chilled version with parmesan.
Delia Smith's Roasted Tomato Soup....takes a while to prepare...you will never want another tomato soup!
My leek and watercress soup has has great compliments.
A huge home-made Minestrone, with whatever vegetables are available, this is a meal in itself, with some crusty fresh bread, be sure to add some white wine, and a tin of drained cannelini beans. Enjoy!