If you're a white meat lover (and I am) you can't beat the Cornish cross. Yum, yum, yum. But I hate raising them. True, I got a bad batch, they were sick with something, didn't grow right, (they were 2 pounds at 9 weeks!) and I never got to eat any of my homegrown ones as they all died of whatever they were sick with. Two of 80 survived, both hens, and I kept them on as layers for a while but they died from the heat in the summer at about 9 months old. Those two did finally start growing, at time of death they were about 15 pounds each. They were lazy, disgusting, stinky, greedy, and just not right. I won't do them again, though I do like to eat them.
Of all the homegrown birds I have tried, I really like Buff Orpington. I processed some spent hens (5 years old) last year and those girls were MEATY! Not really any good for fast cooking (frying, baking, grilling) but delicious in the crock pot. So much flavor.
I had a Cornish bantam, and though I never ate her, I wanted to lol. She was only about the size of a big quail, but really muscular. When I can get chickens again, I'm going to get a bunch of them. I'm also going to experiment with crossing large fowl Cornish game and Buff Orpingtons for a slow-growing free range meat bird.