Originally Posted by fris

for beginners genesis is probably the best route if you want to do your own child themes, the others for actually using it, are good, but if you want to do any custom code and you arent very well versed in wordpress it might be tough, plus genesis has some nice custom child themes.

if you want a framework that is free, bones and roots are good, i have been using bolts lately.

https://github.com/aliso/bolts