Good topic Grump even as more of a forward lover!
For SD our best Full Backs have been over decade generations really-
Ted Holdsworth- after being a star Full Forward in the late 1930s including kicking over 100 goals a season twice he was converted to a Full Back after where he also starred, 142 games from 1935-47.
Tim Barker- was our star Full Back in the 1950s in what was a struggling side, Swan Medallist 1952, 239 games from 1944-59.
Joe Lawson- great Full Back in our 1960s Premierships, Swan Medallist in 1958 & our Full Back in our Team Of The Century, 235 games from 1955-66.
Tom Mullooly- after starting as a forward and even on a wing was moved down back where he made the Full Back position his own for us over many years in the 70s & 80s, a beautiful long kick he was a Premiership player in 1982 & 84 (missed 83 with injury), 246 games from 1971-86.
Rod O'Neill- started as a Full Forward in his first year or 2 before being switched to Full Back in the early 1990s, also had a thumping long kick and one of the first running back their judgement Full Backs I can remember at SD, Swan Medallist 1996, 135 games from 1989-98.
Tallan Ames- played everywhere in his early days Ruck, wing, up forward before Brian Dawson converted Amesy into a Full Back where he could use his long arms to spoil, was physically strong enough to wrestle with the FF's and could utlise his athleticism to run off them when the chance came, Swan Medallist 2011, Premiership player 2010, 262 games from 2002-2017.
Although they played most of their careers in the afl some other former Swans custodians worth recognising are- Stephen O'Reilly & Alex Rance.