WOw- thats a difficult question to answer, between so many great Orioles games back in the glory days, and at one time seeing every Md Terps game...I was very fortunate....I was at the World Series both in 1979 and 1983, but as big as those games were for us, none stood out as the biggest game because there were no dramatic finishes in those and in one world series ('79) the Orioles actually lost all the games I attended....
The 1982 regular season series finale was very special in Baltimore...
The Birds had come on like gangbusters down the stretch to cut the division lead to 3 games with 4 games left to play, meaning we needed to sweep all 4 games from Harvey's Wallbangers....
I attended all four games, friday night double header sweep, the saturday afternoon blowout and on the final sunday of the 1982 season, a classic match up between Jim Palmer and Don Sutton....in the finale, Robin Yount led off the game with a homerun to right field and it was all downhill from that point on, the O's lost the division coming up one game short one the final day....but that was about as memorable a series as I can ever remember...it was also Earl Weaver's last game...
The team remained focused and completed the job the following season , winning it all over Philadelphia in 5 games...but I will never forget that run on that final weekend, Memorial Stadium was never louder!