I have:
Vegan Fire and Spice - Robin Robertson
Vegan Planet - Robin Robertson
River Cottage Veg! - Hugh Fearnley-Whittingstall
Veganomicon - Isa Chandra Moskowitz and Terry Hope Romero
Vegan with a Vengeance - Isa Chandra Moskowitz
Appetite for Reduction - Isa Chandra Moskowitz
I have another one, which escapes me (its at my other house) and I can't find it on amazon to tell you the name of it (that and I'm being lazy). The Isa Moskowitz books are hands down my favourites, though I haven't cooked enough from the Robin Robertson books yet to make a firm decision (I only got them the other week). The Hugh Fearnley-Whittingstall book I brought on a whim (and because it was half price in smiths). Fearnely-Whittingstall is an omnivore, and makes no pretence to be veg or anywhere close to it, but he released this book to try and get more of us to eat more veg. The recipes are delicious and of those which aren't already vegan most are easily veganised without any sacrifice of flavour!
These books are currently in my basket/on my wishlist (there are more, but these are the books I'm going to get first):
Hearty Vegan Meals for Monster Appetites: Celine Steen and Joni-Marie Newman
The Enlightened Kitchen: Fresh Vegetable Dishes from the temples of Japan - Mari Fujii
The Asian Vegan Kitchen: Authentic and Appetising Dishes from the Continent of Rich Flavours - Hema Parekh
Buddha's Table: Thai Feasting Vegetarian Style - Chat Mingkwan
Eastern Vegetarian Cooking - Madhur Jaffrey
Vietnamese Fusion: Vegetarian Cooking - Chat Mingkwan
Dakshin: Vegetarian Cuisine from South India - Chandra Padmanabahn
Contemporary and Traditional Japanese Cooking: Simple, Delicious and Vegan - Miyoko Mishimoto Schinner
I like Asian Cooking

. I also have a lot of vegetarian cook books/recipes and I regularly buy Vegetarian Living and Cook Vegetarian. Vegetarian recipes are often easily veganised (though I know you're vegetarian, don't forget vegan cooking! Its often just as delicious). Also, don't forget
http://www.vegweb.com
I hope this helps

EDIT: It occurred to me, that I could just link you to my amazon wishlist:
http://www.amazon.co.uk/registry/wishlist/1GNE4YMA5OR52
EDIT 2: Okay, I remembered it: How it all Vegan - Sarah Kramer and Tanya Barnard