Last place I hade a steak like this was at River Stone Chophouse, in Suffolk, VA. 12 ounce New York Strip steak cooked rare. I haven't had it, but Gowolfpack has had their Porterhouse. Don't recall what he said about its tenderness, but their regular Porterhouse is 24 ounces...might not have been fork-only.
Breck's in North Charleston, SC surprised me the first time I ate there while on shore duty back around 2001-2004. Little hole-in-the-wall place you'd never suspect of having steak that good. Well marbled T-bone that I found I didn't really need my knife for.
Back in my home town of Lafayette, Indiana, there used to be a place called Sarge's (Sarge Oak?). No longer around. Dad and I went there when I was young and he warned me before we walked in: "Don't order your steak well done. If you do, Sarge will personally cook it to death and serve it to you himself and watch you eat it. And don't ask for ketchup." Don't rightly recall a steak that tender there, as it was more than 40 years ago and I was in my medium-cooked phase. But I do remember it being one of the best.
Don't remember the little restaurant I ate at my last day in Lisbon, Portugal a couple years ago, but I ordered the steak dinner and when the waiter asked how I wanted it cooked, I said "chef's preference, but absolutely no more than medium-rare". Turned our he was the chef and apparently extremely happy to have an American who didn't want his beef over cooked! No knife was required.
Buying your own steak? I used to buy from a butcher all the time, but haven't much in years. Why? Well, for the longest time my wife (and for years after our kids came along) just didn't eat beef...and when they did, I caught Hell from her if I tried cooking and serving beef anything except well done for her and the kids. It was just miserable for me putting up with her comments about it all the time to the point it wasn't enjoyable to eat a steak myself...and being the odd-man-out at the dinner table while everybody else had chicken, pork, or whatever never felt right. So I just quit buying it.
My recommendation is to find a good butcher shop, get to know the butchers there, and if they're good, they'll understand grade prime beef and what you want for GOOD prime New York Strip steaks. (Or whatever.) I'm not a butcher...so I don't understand all the nuances of what constitutes how the meat is graded and such. I know the basics and that's it.
I'm not a chef, either. But I'm half decent on the grill with meats and beef isn't that difficult. Hard to overcook, in my opinion, the rarer you like your beef. A good high-temperature seer to lock the juices in and cook more as you like from there. Best hot off the grill.
My opinion is well marbled T-bone seems to be the the easiest for me to get fork-tender for some reason. Especially closer to the bone.
One thing is sure, though, in my opinion...well cooked prime steak is totally awesome, whether it's actually fork tender or not! How can you lose with that?