Which console wins in terms of the design of the system really just comes down to personal preference and little else as far as I’m concerned, as they are both well built and have their own aesthetic charms, so take your pick:
At least on paper and by the normally-touted numbers, the SNES wins in terms of specs, but not so much once you look beyond the surface level. The Genesis is actually more versatile and powerful under the hood in many ways and really only falls short in terms of colours, transparency, background layers, some built-in custom effects like SNES’ Mode 7 background scaling/rotation/shearing, and overall audio, but it also betters the SNES in many technical areas in real-world use and when in the right hands (most games run in a higher horizontal resolution, it’s less likely to suffer slowdown when there’s a bunch of stuff on-screen due to the faster CPU, it can display more sprites in a line before things start to flicker, it’s much faster at proper 3D, etc).
Actual Winner: Tie
Well, unless you factor in the various in-cartridge enhancement chips that can be used with each system and indeed were used on the SNES regularly: SVP on Genesis (used by just one game), Super FX/DSP/SA1/etc on SNES (used by over seventy games).
Bonus Point: SNES
There are the more obvious things like the amount of colours, background layers, sprites on screen and so on, but there are also some built-in graphical effects and tricks to take into account with each console: Both the SNES and Genesis can do line/row scrolling, column scrolling, layer and sprite priority shifting, and DMA, but the SNES can additionally do HDMA, background scaling/rotation/skewing, proper transparency via colour math, window/shape masking and mosaicing, and the Genesis has a built in window mode for drawing status bars to the screen more easily.
Some games that pushed the limits of the SNES:
Some games that pushed the limits of the Genesis:
Each console has its graphical strengths and weaknesses: SNES games tend to look nicer due to the higher number of colours, added transparency, and extra background layers, and they often show off fancy background scaling/rotation/skewing effects, whereas Genesis games tend to have more screen space for better viewing of the level, which is especially important in fast scrolling games or games where it benefits to see as much of the view as possible, and they suffer from slow down and flicker far less frequently, even when there’s a lot of action happening on screen.
At a more immediately appreciable surface level though, I think the SNES games tend to look better overall, particularly the first party games that work to the system’s strengths better than most, and any potential issues with slowdown and flicker can be overcome with good design and well-optimised code.
Also, and this is an important feather in SNES’ cap, the SNES can and does regularly use additional enhancement chips in the carts to the push the system well beyond its stock limitations and often beyond the Genesis’ capabilities too, and there are many games that utilise this feature of the system to great effect, starting right from day one with the launch title Pilotwings. Most of the underlying technical shortcomings of the system can be negated with this ability, and it’s pretty much unique to the SNES since only one Genesis game ever used such a feature whereas over seventy SNES games took advantage of it, sometimes rather spectacularly (Star Fox, Doom, Yoshi’s Island, Super Mario Kart, Street Fighter Alpha 2, Chatty Parodius, Super Mario RPG, etc).
Both the SNES and Genesis are capable of outputting mono and stereo sound (with some pretty big caveats in Genesis’ case depending on what hardware model you have), but the SNES can also do Dolby Surround sound. The SNES uses PCM samples for music that often sounds more orchestrated and rich, and the Genesis uses FM synthesis for a more digital/electronic audio experience that’s usually well suited to more dance/techno-sounding music and heavy beats. The Genesis music and fx do tend to sound clearer and less muffled than SNES much of the time due to the SNES’ use of the aforementioned PCM samples, but conversely, Genesis sound also tends to be a bit more tinny, harsh and scratchy on the ears at the same time.
*It’s worth noting that the four Genesis’ PSG sound channels were mainly included for backwards compatibility with Master System games, and, while they can be used to augment the seven FM channels for a total of ten audio channels, they are very limited and sound noticeably artificial and dated. So, it’s nice that they are there and can be utilized if necessary, but they’re not something that can suddenly make the Genesis sound better than the SNES. Plus, around half of the Genesis’ software library did not use the extra PSG channels at all.
Here are some examples of soundtracks from each console:
Some people prefer the Genesis’ more arcadey sounds, but I [and many others] prefer the SNES’ more orchestrated sounds and also feel it’s ultimately far more versatile and well rounded in the sound department overall.
Edit: The following video has a figure of 869 total officially licensed games for Genesis/Mega Drive, not including any new indie/homebrew titles released in more recent times, so that’s a correction to the number I have above that was originally sourced from Wikipedia: https://youtu.be/NlYcnbHiTsk
Standout SNES games: Super Mario World, Super Mario Kart, F-Zero, Yoshi’s Island, Star Fox, A Link to the Past, Super Metroid, Street Fighter II Turbo, Mortal Kombat II, Castlevania IV, Super Aleste, U.N. Squadron, Donkey Kong Country series, Super Mario All-Stars, Super Mario RPG, Chrono-Trigger, Super Ghouls N’ Ghosts, Final Fantasy series, Mana series, Mega Man series, Sunset Riders, Zombies Ate My Neighbors, Super Punch-Out, Wild Guns, Parodius series, SimCity, Pilotwings, Cybernator, Tetris Attack, Super Tennis, International Superstar Soccer, Batman Returns, Contra III, Super Smash TV, Actraiser, Bomberman series, Earthbound, Turtles in Time, etc.
Standout Genesis games: Sonic series, Contra: Hard Corps, Phantasy Star series, Gunstar Heroes, Street Fighter II: Champion Edition, Mortal Kombat series, Thunder Force series, Ristar, Rocket Knight Adventures, Sparkster, Shining Force 2, Herzog Zwei, Landstalker, Shinobi series, Streets of Rage series, Hyperstone Heist, Pulseman, Beyond Oasis, Ghouls N’ Ghosts, Aladdin, a whole load of EA Sports games, Earthworm Jim, Musha, Road Rash series, Strider, Comix Zone, Strike series, Toejam and Earl, Golden Axe series, Mega Turrican, Ranger X, a whole load of Disney games, Adventures of Batman and Robin, Dynamite Headdy, Castlevania: Bloodlines, Alien Soldier, Virtua Racing, etc.
Genesis was generally stronger in the action and sports category and SNES was generally stronger in the platformer and RPG category. Which games you enjoy the most comes down to personal preference, but the SNES ultimately has far more games, and to this day more SNES titles still appear near and even at the top of most Best Games of All Time lists, which speaks to the truly great and timeless quality of that console’s best titles.
In terms of the amount of inputs, the SNES clearly comes out on top. And those inputs offer far more versatility too, from using the shoulder buttons to strafe in Doom, as air brakes in F-Zero, or to do a barrel roll in Star Fox, to using the diamond-shaped face button configuration to shoot in one of eight directions at the same time as moving in one of eight directions with the d-pad in games like Smash TV and Total Carnage, and allowing easy weapon and item selection in games like Zombies Ate My Neighbors and B.O.B. And the default SNES controller is perfectly capable of playing a game like Street Fighter II properly too, a game that uses six attack buttons, whereas you’d need to go out and purchase a different controller for Genesis at additional cost to get a similar experience (at least for around half of the people who owned a Genesis system, as it didn’t come in the box as standard until later on in the console’s lifespan). So this one really isn’t close as far I’m concerned.
The figures for Genesis are all over the place and go from the low 30 million mark to around the 40 million mark depending on the source. I do not trust the sources touting the highest numbers at all, as they’re mostly based on estimated figures from gaming journalists and third party analysts, who are rarely reliable in my experience, and I think most reliable sources usually sit around 35 million as being pretty fair and accurate. The SNES numbers are official and come from Nintendo directly. Either way, the SNES sold around 15 million more units that the Genesis,.
Ultimately, when I put it all together and consider the sum of all parts, it’s impossible for me to come to any other conclusion than the SNES being the overall winner, with its better graphics, sound, controllers and games. But, of course, each person is free to love whatever console they choose and indeed love them both equally if they like too.