While Claude and GPT are still the two best choices, Gemini seems to be catching up on coding agent index with agy-cli

The Artificial Analysis Coding Agent Index, which evaluates agents based on model and harness across three coding evaluations, indicates that Gemini 4 Argon is catching up to Claude and GPT. Gemini 4 Argon, using Google's promotional pricing and not yet publicly available, scored 64 in Antigravity CLI at $5.84 per task, less than half the cost of Sonnet 5.5. In comparison, GPT-6.1 Sol scored 63 in Codex at $1.04, roughly one-sixth of Argon's cost.