Gemma 2 27B is currently the best performing 'open' model [license is non-commercial].

The Unsloth team have a blog post up where they've made fine-tuning Gemma 2 require less VRAM, and also have extended the context window.

They've also updated their 'mistralified' PHI-3 models to Microsoft's June update of PHI-3 which sees some performance increases as well.