You should really go and explore them for yourself. I’ve been having fun identifying highs and lows for the major awards as follows:
Highest-ranked Hugo Best Novel finalist: Harry Potter and the Prisoner of Azkaban, by J.K. Rowling (2000) - winner that year was A Deepness in the Sky
Highest-ranked Hugo Best Novel winner: Harry Potter and the Goblet of Fire, by J.K. Rowling (2001)
Highest-ranked Hugo Best Novel finalist of the twentieth century (which ended in 1999): Slaughterhouse-Five, by Kurt Vonnegut (1970), beaten by The Left Hand of Darkness
Highest-ranked Hugo Best Novel winner of the twentieth century: Ender’s Game, by Orson Scott Card (1986) - just a smidgeon behind Slaughterhouse-Five.
Lowest-ranked Hugo Best Novel winner: not surprisingly, They’d Rather be Right, by Mark Clifton and Frank Riley (1955)
Lowest-ranked Hugo Best Novel finalist: Second Ending, by James White (1962), beaten by Stranger in a Strange Land
Lowest-ranked Hugo Best Novel winner this century: A Memory Called Empire, by Arkady Martine (2020) - just behind Hominids by Robert Sawyer (2003); but I think this year’s winner will rise.
Lowest-ranked Hugo Best Novel finalist this century: The Sky Road, by Ken MacLeod (2001), which coincidentally I have just started rereading.
If you want to count the Retros, the lowest-ranked Best Novel finalist ever is this year’s winner, Shadow over Mars, by Leigh Brackett (1945), though a 1946 finalist, Red Sun of Danger/Danger Planet, by Edmond Hamilton aka Brett Sterling, didn’t even make the chart; the highest-ranked Best Novel winner is Fahrenheit 451 (1954); and the highest-ranked Best Novel finalist is The Lion, the Witch and the Wardrobe (1951), beaten by Farmer in the Sky.
For the Nebulas:
Highest-ranked Best Novel finalist is A Game of Thrones, by George R.R. Martin (1995), beaten by The Moon and the Sun
Highest-ranked Best Novel winner is Ender’s Game, by Orson Scott Card (1986)
Highest-ranked Best Novel finalist this century is A Clash of Kings, by George R.R. Martin (2000), beaten by Parable of the Talents
Highest-ranked Best Novel winner this century is American Gods, by Neil Gaiman (2002)
Lowest-ranked Best Novel finalist is Rogue Dragon, by Avram Davidson (1966 - a very long shortlist for the first Nebula award won by Dune)
Lowest-ranked Best Novel winner is No Enemy but Time, by Michael Bishop (1983)
Lowest-ranked Best Novel finalist this century is From the Files of the Time Rangers, by Richard Bowes (2007), beaten by Seeker
Lowest-ranked Best Novel winner this century is A Song for a New Day, by Sarah Pinsker (2020 again, therefore likely to rise)
For the BSFA Award:
Highest-ranked Best Novel finalist is American Gods (2001), beaten by Chasm City
Highest-ranked Best Novel winner is Rendezvous with Rama, by Arthur C. Clarke (1973)
Highest-ranked Best Novel finalist last century is Neuromancer, by William Gibson (1984), beaten by Mythago Wood
Highest-ranked Best Novel winner this century is Ancillary Justice, by Ann Leckie (2013)
Lowest-ranked Best Novel finalist on record (some years seem to be missing) is The Memory Palace, by Gill Alderman (1996), beaten by Excession
Lowest-ranked Best Novel winner is Grainne, by Keith Roberts (1987)
Lowest-ranked Best Novel finalist this century is Cyber-Circus, by Kim Lakin-Smith (2011), beaten by The Islanders
Lowest-ranked Best Novel winner this century is End of the World Blues, by Jon Courtenay Grimwood (2006)
For the Arthur C. Clarke Award:
Highest-ranked finalist is The Time-Traveller’s Wife, by Audrey Niffenegger (2005), beaten by Iron Council
Highest-ranked winner is the very first, The Handmaid’s Tale, by Margaret Attwood (1987), also the highest-ranked finalist last century
Highest-ranked winner this century is Station Eleven, by Emily St John Mandel (2015 - the year I was one of the judges)
Lowest-ranked finalist is Streaking, by Brian Stableford (2007) which is almost off the scale, beaten by Nova Swing
Lowest-ranked winner is Dreaming in Smoke, by Tricia Sullivan (1999)
Lowest-ranked finalist last century is again Grainne, by Keith Roberts (1988), which for the record I rather liked, beaten by The Sea and the Summer
Lowest-ranked winner this century is Bold As Love, by Gwyneth Jones (2002)
But really, as I said, go explore the tables for yourself - great fun. If I had time I'd do the same calculation for LibraryThing, which would produce similar results with quirky differences.