Few ideas
1. A monitor with S-PVA blacks, S-IPS whites and color reproduction, TN response time and refresh rate, and "retina" resolution (~8*4K for 24''), and eIPS price.
2. Shared memory (GPU-CPU) for PC. Also, ECC as standard for all PC's.
3. FP128 (quad precision) capable CPU (and GPUs), today's CPU's can emulate FP128 with performance in KFLOPS, probably.
4. GPU and CPU that turns fans off when not in 3D. 0dB.
5. (maybe offtopic) GTA-like video game with real models of Cars, Bikes... (Bulldozers, Bicycles, ATV's, Boats, Aeroplanes, Helicopters...), in optional first person view (like Far Cry 2), and RPG system (quests, leveling...)....