Another vote for CrashPlan. Because:
-CrashPlan can replace your local TM backup too, since it's encrypted, seems to be less overhead than TM in terms of resources, and has compression and data deduplication built in (doesn't backup the same block of data twice, like Dropbox)
-CrashPlan supports all HFS+ file streams, like file label colors, symbolic links, "where from" attribute for spotlight, custom folder icons, etc. No other backup service except Arq and Dropbox seems to do the same (Dropbox doesn't support file label colors, but supports everything else).
-CrashPlan has an option where they send you a 1TB disk to seed an initial backup if you'd like
-They have unlimited plans for unlimited number of computers
-Their tech support is a little slow, but they're knowledgeable and try to help you out if they can
-You can create an encryption key separate from your account login. This means Crashplan is not in possession of the key that would decrypt your data. This also means you lose all your data if you lose your key.
-CrashPlan app has extensive file exclusion/inclusion controls
-Like most/all these services they are not very transparent about something going on with their servers.
-Unlike TM, you will need to restore your Mac, install CrashPlan, then bring all your files back. They also have an option to ship you a drive with your data - costs money to do that.
-Has the same clunky restrictions that TM does with filevault-ed accounts, but if you have only one filevault-ed account then you can install CrashPlan inside it and have timely backups.