Hardware:
8bit - Master System > NES The MS was the stronger console, but wtf with the pause button on the console itself rather than the controller? A narrow victory.
16bit - SNES > MegaDrive Mode7, SuperFX, etc.
32bit - PS1 > Saturn Saturn lost at 3D, but excels at 2D. 3D was the way forwards.
64bit - N64 > Atari Jaguar 'nuff said.
128bit - Xbox > Gamecube > PS2 > Dreamcast Xbox is a powerhouse, the DC weakest because it had such a head start.
Next-gen (256bit?) - PS3 > Revolution > Xbox360 360 is weakest for coming out first, but the others are speculative. PS3 is expected to be twice the power of the 360.
Software (games):
8bit - NES > Master System Super Mario Bros, Final Fantasy, Metroid, Zelda, etc.
16bit - SNES > MegaDrive As above.
32bit - PS1 > Saturn Soul Blade, Armored Core, FF7. etc.
64bit - N64 > Atari Jaguar Name a Jaguar game other than Cybermorph or Doom. Go on.
128bit - Gamecube > Dreamcast > PS2 > Xbox Again, Nintendo continue to make the best games. Dreamcast had a bundle of absolute classics though, earning its place in 2nd. PS2 has many excellent games, but many bad ones too; lower good game bad game ratio. Xbox has many multi-format games & PC ports. Little original.