There's also Honeycomb if you're more focused on tracing, and Prometheus/Grafana if metrics are what you care about most.
I think it depends if you're just looking at price or other factors as well, I'd say the incumbents would be Grafana or Elastic. Though they both have a bit of their pitfalls - Grafana Loki doesn't handle high-cardinality search well (ex. search by ID) versus Elastic is super heavy to have self-hosted and involve some manual schema management. Though they're both very mature offerings and can likely flex to arbitrary workloads.
On the other side of things I'd say Signoz or HyperDX (what we're building) can work as well, though again each tool has its set of UX tradeoffs it's made so far and it really depends on what workflows you care for the most.