For an offsite backup, Backblaze is fantastic. Unlimited storage for $5/month and the client works perfectly. It's not highly-redundant or anything, so use it in addition to a local backup.
CrashPlan is the next-best option if you need Linux support, but the client isn't as good.
CrashPlan is the next-best option if you need Linux support, but the client isn't as good.