As a web/app developer there's nowhere to go unless third party apps mature. The OS itself really doesn't matter.

What I feel unreplaceable, (I don't mind free or paid)

- Sequel Pro (Windows may have HeidiSQL)

- Source Tree (Windows one exist but not Linux.)

- Better Touch Tools

- Forklift / Transmit (That does dual pane file browser / sftp remote browser)

- QR clipboard (To pass URL to phone)

- Xcode

Web browser, email and Jetbrains stuff are available all over, so those are fine though.

It's sad and ironic that I can't recommend a good git gui client to a friend who uses Linux daily.