The top 5 attendances at the Adelaide Oval (and for any games played in Adelaide) for rugby league have been:
28,884 - St George vs Balmain 1991 (largest non-Finals NSWRL crowd of 1991)
27,435 - Adelaide vs Hunter, SL 1997 (Rams record attendance, also their first ever home game)
21,492 - Roosters vs Melbourne, 2017
20,246 - St George vs Canberra, 1993
18,892 - St George vs Brisbane, 1992.
I was at every one except last years, and tonight.
St George played home games in Adelaide from 1991-95 mostly because their then long time sponsor Penfolds is an Adelaide based company. The Dogs played home games against the Storm in 2010 and 2011, but with low attendance (10,350 in 2010 and 9,963 in 2011), they abandoned it and we didn't get a game again until 2017.