Ive been to so many (hundreds & hundreds) it's hard to pick one out.

The 1979 FA Cup Semi Final replay Liverpool v. United at Goodison always sticks in my mind (I'm in this picture somewhere near the front).



As does the 1985 FA Cup Semi Final replay Liverpool v. United at Maine Road.
Happy days.



I've been to 5 European Cup finals with the 1999 one being a lifetime highlight, not a great game though.

The 1978 game at Old Trafford between United & WBA (3-5) was a cracker of a game.