Like everyone else I have quite a few but I will only mention two.
#1 Alaska - on the Kanektok fishing silvers in fall of 1985, landed 177 in two days of fishing. 50 or so on flys and the rest on hardware. Never saw another fisherman the whole time accept 2 or 3 boats that motored past me up river and were never seen again. Had my tent set up on a 100 yard sand bar. Woke up the second morning and the river was like glass the bottom looking unusually dark. I put my fish locators on and was dumb founded as there were 100s if not thousands of fish sitting only a couple of feet from shore extending down river for as far as I could see. I proceeded to catch fish after fish after fish. I know I will never have fishing like that ever again.
#2 Day after Christmas on the Kalama, 2001. I was sick for several days during Christmas and finally started feeling better around noon the day after Christmas. I told my wife was going to the Kalama for the afternoon. Arrived up in my favorite area around 2:30pm. Hiked down to the river and there was virtually no one around. First cast..fish, second cast..fish, then it was a blurr after that. I ended up going 9 for 11 in 2 1/2 hours of fishing. Went down there the next day and went 8 for 9. There were 2 or 3 summers mixed in the catch but most were chrome bright winters. Ended up going 17 for 20 in about 10 hours of fishing. I doubt I will ever top that for steelhead as far as shear numbers of fish in a short period of time goes.