If you are looking for the best Multi-purpose and Multi-Niche odoo theme without e-commerce features on Odoo Store, then here is the solution. Theme Limpid is the best theme with built-in responsive and high performance functionalities,

Theme ALAN is one of the most powerful, amazing and flexible themes on Odoo store. Alan is a professional and multipurpose bootstrap based theme for printing and other businesses. The code is very well organized and modular.