I've been back and forth on Genesis starter themes over the years.
I made one a while back with the Genesis Sample theme, again with a Sass and Gulp workflow, but over time realized I had changed up so much code and shifted so many things around that it had become more of a burden than a helper.
Then I came across Bill Erickson's starter theme and really enjoyed using it for a month or two, but it just has a bit too much going on for my taste.
Thus, I decided to step back a bit and simplify things.
Here's what I did:
First, I grabbed the latest Genesis Sample theme from Studiopress (3.0).
Second, I decided not to change anything at all except for the assets and the workflow. That means no gutting functions.php and no creating a custom plugin, by default, to throw everything in.
I used Sridhar Katakam's Sass files to replace the default CSS.
Finally, I added WP Gulp to incorporate a full-featured Gulp workflow
So if you are looking for a nice, simple, Sassified, Gulp-driven Genesis Starter theme to begin your projects with, this one is simple to use and based off of the latest and greatest Genesis Sample theme.
Here it is: Genesis Starter Theme