I think they're all fine. Cursor is popular and charges a flat fee for model calls (interposed through their model call router, however that works). Aider is probably the most popular open source command line one. Claude Code is probably the most popular command line agent overall; Codex is the OpenAI equivalent (I like Codex fine).

later

Oh, I like Zed a lot too. People complain that Zed's agent (the back-and-forth with the model) is noticeably slower than the other agents, but to me, it doesn't matter: all the agents are slow enough that I can't sit there and wait for them to finish, and Zed has nice desktop notifications for when the agent finishes.

Plus you get a pretty nice editor --- I still write exclusively in Emacs, but I think of Zed as being a particularly nice code UI for an LLM agent.