Just done a bit of research and Star Ocean is indeed the largest SNES game, coming in at 48 megs.

Source: http://www.fantasyanime.com/valhalla/starocean_about.htm

I think those "megas" were megabits and not bytes.

So dividing by 8, maximum genesis game was 5 MB - Street Fighter and Ultimate Mortal Kombat - and SNES was 6 MB - Tales of Phantasia

(I think...)

Now that you mention Street Fighter I remembered those 40MB.

I've even found the add that they used in Spain! http://pixel2pixel.files.wordpress.com/2011/08/super_street_fighter_ii.jpg?w=560

"40 Megas in Action" "Only for the brave"

Imagine if we still thought that way, today.  Memory size=quality.  Wow, we were stupid.

I love statistics and it's practically impossible to find a list of this so I wanna be the first. Also it can give us a good idea of what the average disk size could be for the 8th gen if there is a noticeable pattern to how much a game size goes up each gen.

PS3 are usually 10-50GB, most are about 15GB. but in reality most of the disk is constructed with back up sets of data so it can read faster... I wouldn't honestly trust the actual size of a game unless it is downloadable from the PSN store.

In terms of actual game content most PS3 games will mirror the X360 version (some of them I think have less compressed sound) and it's rare X360 games go over 1 disc (ie 8.5GB)

I think your max PS1 stats are wrong. Weren't there a bunch of games that came on 3 or 4 CDs?

no nes games were ever 4KiB, the smallest, Galaxian, was 8 KiB
2600 2KiB to 32 KiB average was probably 8 KiB maybe 4 KiB
5200 8 KiB to 48 KiB (bounty bob strikes back is the 48 KiB game) average game was probably 16 KiB
colecovision 8Kib to 32 KiB again average was probably 16 KiB
Atari 7800 32KiB to 144 KiB (only Alien Brigade and Crossbow (I think) were 144KiB)
(I use mode for averages in this case, think it is the best measure of central tendency)
Neo Geo 2.75 MiB to 89.5 MiB, not sure about the average size.

Actually until they switched to the new XGD3 DVDs (after Halo:Reach?), single disc 360 game DVDs were around 6.8GB max because of security.

Rage which makes use of the new XGD3 DVDs, is the first game that max's out the XGD3 disc @ 7.8GB.

"The maximum space for game data on 360-discs currently stands at 6.8GB with 1GB of the 7.95GB dual layer DVD alloted to anti-piracy and other security measures. Digital Foundry believes the video partition has “either been drastically reduced or omitted completely in the new format Microsoft is looking to roll-out.”" - source

Here's a list of multi-disc 360 games:

Battlefield 3, Blue Dragon, Castlevania: Lords of Shadow, Dead Space 2, Dragon Age Origins: Ultimate Edition, Fallout 3: Game Of The Year Edition, Final Fantasy XIII, Forza Motorsport 3, Forza Motorsport 4, Infinite Undiscovery, L.A. Noire, The Last Remnant, Lost Odyssey, Mafia II Platinum Hits, Magnacarta 2, Mass Effect 2, Mass Effect 3, Max Payne 3, Metal Gear Solid HD Collection, Rage, Star Ocean: The Last Hope, Star Wars: The Force Unleashed Ultimate Sith Edition, The Elder Scrolls IV: Oblivion Game of the Year Edition and The Witcher 2.