Best AI Gateway?

What AI gateways work well? We currently use Anthropic's router directly for our AI agent (on val.town) but are considering adding OpenRouter or the Vercel AI Gateway, or something else entirely.

I know little about gateways except that they seem to be the new VS Code forks (i.e. everyone is doing it). My cursory research tells me that OpenRouter has the most models/providers, but charges a 5.5% pay-as-you-go platform fee (we pass-through inference costs to customers) and doesn't support features like prompt caching.

We're mostly a Cloudflare shop, and I learned minutes ago that they, too, have an AI gateway--but so far the "Best LLM Gateway 2026" type articles I've found are published by...companies with a gateway