I was just wondering what those with dedicated servers use for backup solutions. Is RAID1 really enough? Do you use some kind of NAS?

RAID is not a backup solution. You should have another drive for backup whether that be on the server or elsewhere.

For ourselves as well as our clients cpwebhosting.net use a complete bare metal recovery solution that allows us to recover our servers as well as those of our clients in less then 30 minutes from a completed server crash.

I think RAID1 is enough and never use any other form of backup. Even RAID5 would be better than RAID1, but both are prone to hackers defacing data. An actual backup somewhere else would allow you to restore data after a server compromise.