There are lots of great starter themes and frameworks out there now. Some better than others. I created this one when I couldn't find the perfect match that I was looking for. You should check it out, because, well, it's pretty cool!
I love the default themes that WordPress gets bundled with now. TwentyTwelve and TwentyThirteen are both great starting points for creating new themes. They're clean and fairly minimal, which is what I like. They're developed by the same guys who code WordPress so you just know that when you look through the code, it's gonna be some quality work.
I used TwentyTwelve and Underscores (_s), another theme by the talented Automattic folk, as a starting point for creating Quark. After upgrading the base html with a 12 column grid, I then added my own features that I constantly use when creating themes for my own clients. It has a minimal amount of styling so that it's not too difficult to make into your own. There's no unnecessary bloat from including things like sliders, forms and shortcodes. These are best served by using dedicated plugins that match up with your own requirements. I find there's nothing more annoying than using some framework or theme with all these extra features that you don't need or never use.
If you're using Quark and interested in helping translate it into your own language, that would be awesome! Simply head over to the GlotPress site on WordPress.org, select your language, and dive in! If you're new to translating WordPress, you can have a read through the Translator Handbook to get started.