I've had a faddy couple of years too (curse you, James Wong!), but have now calmed it down a bit.
Asparagus peas - vile
Callaloo - not worth the bother
Cucamelons - I like. Great crop 1st year, ok 2nd year, but I've jot bothered this year.
Tomatillos - I do like, but I got a bit fed up of them, as I had soooooo many last year and ran out of ways to use them up. But the flowers were great for bees, and I will definitely do again.
Salsify - agree with faff. And it sat in the ground for so long.
Inca berries / physalis (yes, I know you said veg) - I like these, and am doing them again this year, although they really need a greenhouse and a long hot season.
What about aggretti - that seems quite fashionable this year?
Broccoli raab /cima di rapa / turnip greens -I really like this, and I aim to grow successionally, but it does bolt really quickly.