I have a 569.4GB file in my torrent list atm. I haven't started it yet, as it exceeds my monthly download allowance by, oh, only a factor of about 5 (assuming I download nothing else for those 5 months).
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I would offer to sneakernet it to you, but postage would kill it, even with a 640Gb laptop drive.
Longest torrent for me was recently: a Kali-linux ISO. I did not have internet at the time, and slowly downloaded it at free wifi hotspots over the course of a week or two.
Usually the largest problem for me is that there's like only one seeder for an obscure origami manual and he's only got 1/3 of it or whatever. Eventually I gave up.
(FWIW, the origami in question might have been "the last waltz" by Neil Elias. Copyright issues on abandonware are grey, and it's not been legally available anywhere for the past 40 years or so.)