All these themes are free though some have commercial variants available. We stated that where applicable. Enjoy!
Shopper
Created by/for: Dessign
Features: eCommerce oriented, super minimal grid layout, needs a few plugins to work at its full potential
License: free for personal and commercial use (GPL)
BiancaA
Created by/for: Theme Junkie
Features: mobile-ready, great for photo-blogging, quiet minimal design
License: free for personal and commercial use (GPL)
Stacker Lite
Created by/for: Theme Furnace
Features: grid-based, social links menu, custom colors and columns
License: free for personal and commercial use (GPL)
Sensible WP
Created by/for: Modern Themes
Features: suited for any type of website, fully customizable, subtle animations
License: free for personal and commercial use (GPL)
Hew
Created by/for: Automattic
Features: prominent social links, colorful menu, focus on content
License: free for personal and commercial use (GPL)
BillyDroid
Created by/for: ThemeShock
Features: elegant color palette, cool slider, Android-oriented
License: Personal
Compass
Created by/for: Ink Themes
Features: highly customizable, seven widget areas, special page styles
License: free for personal and commercial use (GPL)
Ample
Created by/for: Theme Grill
Features: versatile and responsive, huge home slider, editable primary color
License: free for personal and commercial use (GPL)
Sobe
Created by/for: Automattic
Features: basic, blog and content oriented, clean layout
License: free for personal and commercial use (GPL)
Material Gaze
Created by/for: M-E-H
Features: child theme for Stargazer, alternative colors and additional headers
License: free for personal and commercial use (GPL)
Tiles
Created by/for: Viva Themes
Features: awesome Masonry style with hover animations, threaded comments, widget-ready
License: free for personal and commercial use (GPL)
ThemeZee
Created by/for: ThemeZee
Features: responsive, aimed at magazines and new sites
License: free for personal and commercial use (GPL)
Denta Lite
Created by/for: Theme Isle
Features: for the dental industry, clean pleasant look, gallery grid
License: free for personal and commercial use (GPL)
Daily Stories
Created by/for: Best Web Soft
Features: minimal design, ideal for pure blogging sites
License: free for personal and commercial use (GPL)
Responsive Deluxe
Created by/for: Brini Designer
Features: simple design with bright colors, looks great at any size, social links and widgets
License: free for personal and commercial use (GPL)
Lexicon Theme
Created by/for: FabThemes
Features: built on Bootstrap 3, three-column layout, highly customizable
License: free for non-commercial use only
AccessPress Root
Created by/for: AccessPress
Features: minimal design, SEO friendly, fully responsive
License: free for non-commercial use only
Easy Digital Downloads Plugin
Created by/for: Easy Digital Downloads
Features: enables you to sell digital downloads through WordPress, not bloated with features
License: free for personal and commercial use (GPL)
Ridizain
Created by/for: Ridizain
Features: magazine-oriented, grid and slider, full-width design
License: free for personal and commercial use (GPL)
LSX
Created by/for: LightSpeed
Features: minimal framework theme, light and fast, highly customizable
License: free for personal and commercial use (GPL)