It would be interesting to see a modernized C64 -- a C64g where "g" means gigabyte, with specs something like:

* 1 GHZ 6510 compatible processor * 8+ GB RAM

That alone would be interesting, but lets keep going.

* Beefed up SID with 16 bit sound * Beefed up VIC supporting 32 bit RGBA color * Add 3D graphics coprocessor

Probably not really feasible, but I find myself often wondering what it might be like to have the simplicity of a C64 back, but with present day specs.