Huge means: My record is the 1.4 Gigapixel Panorama of Megaton (re-made in 2013).
Most of them were made in 2010 and 2011, on a Radeon 4870 (which broke down) and a Radeon 4890 when not noted otherwise.
Fallout 3, The Pit - Steelworks 4492 x 1989, 2 MB. I just love that red tint of steelworks. Maybe I should redo in higher resolution, if someone requests it ; ).
Fallout 3, View from Vault 101 "slideshow" detail setting, around one and three fps, 19604 x 4012, 15 MB.
I was running a Radeon 4870 512 MB back then. View it at 100% and pan around, you can see A LOT in great detail at large distances.
Fallout 3, Galaxy News Radio Plaza, 23334 x 10863, 25 MB.. Actually a messed up panorama, but the messed up points don't make it look bad but better.
I am the green haired with the bonet and the big gun.
Fallout 3, mega panorama of Megaton full 360°, 55032 x 25790, 144 MB. 1.4 gigapixel. My three compagnions and me are near the centre, in front of the Craterside Supply. Why doing it? I wanted to know how far I can go, and this seems to be the limit. Or I need more RAM (and a CPU which can handle more RAM).
Fallout 3, The Pit, Steelworks after clearing if of Trogs and Wernher, 21340 x 10694, 45 MB, 228 mexapixel.. Made 2013-07-14. I SHOULDN'T have continued my second playthrough of Fallout 3, which I paused when Skyrim came out until now. This game is SOOOOO addictive, so much content, such a good setting.
I've created some other (and larger) panoramas of that cell, but they did not turn out that well.
Fallout New Vegas, The Thorn Arena, facing the nice Red Lucy, 8362 x 4499, 6 MB.
I met her again a little later for blowing off some steam.
Fallout New Vegas, Quarry, 11008 x 2859, 9 MB. I have made another twice as large, but I messed up there at a visible spot.
Normally you cannot see that far, neither the house in the middle and the house on the right would be visible.