1. Graphics Chip
Take gamecube's flipper, implement a second TnL unit and something similar to the 3dfx sage chip. Clock it at 250mhz and expand the texture cache by 1MB
2. Type/quantity of ram
1t-sram, i wouldnt want anything else. 128MB would be cool
3. Processor
PPC750x 1ghz from IBM with openGL extensions, 2 SIMD and fpu
4. Look
Hmm, tough question, im really starting to love the gamecube design, so i would also go for the look BUT it would be a side loader rather than top, less height, would be in silver, blue LED and smaller air vents on the sides
5. Controls
Gamecube controller but with a second Ztrigger bellow the L analog shoulder. Also stereo rumble, a mic port and a line out for headsets (so you can have 4 split screen multiplayer with everyone hearing their own stuffs, less confusing.
6. Internet Connection
Both 56k and BB built in
7. Expansion
uh, outside of memory cards, none.