The amount of repos available to add to F-Droid makes the app selection pretty deep in my experience. Here’s a few:

Izzy Droid - https://apt.izzysoft.de/fdroid/repo

Guardian Project - https://guardianproject.info/fdroid/repo

Ironfox - https://fdroid.ironfoxoss.org/fdroid/repo

Futo - https://app.futo.org/fdroid/repo

Fedilab - https://fdroid.fedilab.app/repo

Molly - https://molly.im/fdroid/repo

Briar - https://briarproject.org/fdroid/repo

Anonymous - https://anonymous.gratis/fdroid/repo

There’s a bunch more repos you can find online, but I’ve always enjoyed having these enabled. Additionally, there’s the Aurora Store from F-Droid, which allows anonymous access to the Play Store. There’s also Obtainium, which will directly access developer’s GitHub/GitLab/Codeberg/SourceHut repos as well.