Hey Tooty...Lambs Quarter is a terrible weed, but I do harvest it to add to a salad. No ones the wiser, either :-D I have gotten away with that for a long time.
Lycopus virginicus and Phyllanthus amarus are probably the most bothersome plants that invade my garden. They don't really bother me that much, however, they can spread very very fast. They are easy enough to pull up though.
Bindweed,..though only coming through from the property on my left,..none on the property to my right,..i have fought it for years and it only advanced to about 12 inches into my garden,..i put up black windbreaker material about four foot high and some 12 inches deep,..the bindweed won't grow towards the dark so what i have is remnants of what was the original invader. Oh i grow Dandelion in flower pots,..lol,..its to feed my Silver Dollar Fish.
I also have lamb quater -but will try it in salad. Getting lot of wild chives. Lot of people said they cook with it -never have.