Titanium Backup is the most powerful backup tool on Android, and then some.
You can backup, restore, freeze (with Pro) your apps + data + Marketlinks. This includes all protected apps & system apps, plus external data on your SD card. You can do 0-click batch & scheduled backups. Backups will operate without closing any apps (with Pro). You can move any app (or app data) to/from the SD card. You can browse any app’s data and even query the Market to see detailed information about the app.