Today I posted sprays's Circle Of The Moon map, which is the largest map we've seen yet - a 16.1 MB .PNG!
I noticed that the Harmony Of Dissonance maps (by Zeric) were put up on the 28th of last month - almost exactly a month ago - and those come in at 11.1 MB and 10.4 MB. A week ago I put up The Faery Tale Adventure map by DarkWolf, an 8.48 MB .png (the map isn't even full scale, wow), and that rounds out the top 4 largest maps, beating out the previous record holder, which was a .JPG (The Citadel Island map from Relentless: Twinsen's Adventure, made by Assassin, 7.23 MB) so the different filetypes don't really make it a fair comparison.
Of course, there's the issue of .PNG compression since we're talking about filesize... sprays thought the advancecomp program was a better compressor than PNGGauntlet (which itself is essentially PNGOut, I believe). If PNGGauntlet/PNGOut was used on the Circle Of the Moon map and truly didn't compress it as much, it doesn't change its heavyweight status as it would still be the largest. I guess the question is how large The Faery Tale Adventure's map would be if it was full-sized?
As I said in the news post, the sudden flow of large maps is interesting. Is there some kind of competition going on to see who can make the largest map? o_0
If there were such things as animated .PNGs (or animated .GIFs that could somehow have 16.7 million colours instead of just 256 maximum), a full-sized, pixel-perfect, animated map of Zebes from Super Metroid would probably be pretty large... >_>