I love Harvey's veggie burgers, in fact that's what I picked up for lunch today, along with onion rings!
They are full of so much flavor, are juicy and taste incredibly fresh! I love that I can pick the toppings and ask for as much or as little as I want, always get extra pickles on the side!
As far as fast food is concerned, Harvey's is hands down the best in my opinion!

Harvey's veggie burgers are amazing. This was the first veggie burger I've tried (I've cut out beef from my diet) and let me say it was darn good!! I didn't know what to expect but it taste way better than any beef burger out there. I love that you can dress it the way you like as well.
The cost is average and the quality is phenomenal.
Try it if you haven't!!