The NEO GEO won the hardware specs race, hands down. The SNES could do things the Genesis could not, like Mode 7 - scaling of a single plane and could display more colors. But, Genesis Had a better Sound chip and had a faster processor. There was also the 3DO, which was 32 bits and a relative powerhouse of a console.
N64 was more powerful in raw specs over the competition, but It also had the cartridge limitation(max size of the carts were 64mb), while the original PlayStation and SEGA Saturn had a CD drive.
other limitations of the N64 hardware:
"While the N64 had some impressive specifications compared to the PlayStation and Saturn on paper, the reality was much different. The RCP, while a very advanced design for 1996, had a serious crutch in that it only had 4Kb of texture memory (compared to the PlayStation which had 1Mb of dedicated video memory, a variable amount could be dedicated to textures). This meant that developers had to make serious concessions in texture design. Two common solutions were to either tile small textures across a surface or resort to Gouraud shading of polygons instead of proper textures."
"When it comes to the actual specs, the Xbox is the most powerful with a 733-MHz processor, leaving PS2 and GameCube in the dust at 295 and 485 MHz, respectively. It also comes with a 233-MHz graphics processor and 64MB of total memory. But instead of dial-up capability, the Xbox allows only a broadband connection for Internet gaming."
"Raw GPU power and feature set does go to the NV2A core that is in the Xbox. Games such as Dead or Alive 3 are perfect examples of how easy it is for developers to write these custom pixel and vertex shader programs as well as how great the results can be.
Both Flipper and the NV2A support texture-compression which plays a major role in the use of higher-resolution textures in games. On the launch titles for the GameCube we've seen a number of lower resolution textures being used compared to the Xbox launch titles. That could just be a sign of the early adopters not taking advantage of the technology yet or it could be due to a lack of main memory bandwidth, it's too early to tell."