OP, much good advice in this thread. I'll add only one more thought...
BUY at least
TWO BIG drives to BOTH be TM or CCC/SuperDuper backup drives. Full backup to both and store one in a secure offsite location like a bank safe deposit box. Then regularly rotate the one in use with the offsite one. This is key to protecting against very real flood/fire/theft scenarios.
Personally, I have no problem at all with TM as my backup solution (10+ years now) but respect Fishrrman posts on this topic. So if you opt to use TM, consider a THIRD drive so you can have at least one regular backup via CCC or SuperDuper too. As FreakinEurekan offered in #2, big drives are cheap... and having too many backups is a much better "problem" vs. having too few.
If I felt some doubt about TM, I'd probably store one of my TM AND a full backup of CCC or SuperDuper OFFSITE, then fetch both when it's time to switch, backup both and then get the latter back to the offsite location ASAP. Or maybe work that option as an in-between backup (between the TM backup swaps).
For example, I'm on a monthly schedule for swapping drives. I've decided about every 4 weeks is the right amount of time for my data protection needs. So if I wanted to mix in a CCC or SuperDuper backup, I might backup that way at about the end of the 2-week boundary:
- end of month: swap TM drives
- mid-month: fetch CC or SuperDuper drive, backup and get it back to offsite storage ASAP
- end of month: swap TM drives again
An approach like this would make my worst case of potential dataloss occur on the 14th- immediately before the update to the CCC/SD drive. To be worst case, the offsite TM backup would have to catastrophically fail (no possible data recovery) and thus the CC or SuperDuper backup would be 29 days out of date. I'd lose the last 29 days worth of new data in a full restore from the CC or SuperDuper drive.
If you are really shaken on TM but still want to use it, you could flip this concept: 2 CCC or SuperDuper drives and 1 TM drive, rotating from home to offsite in the same kind of (regularly scheduled) way.
The main point in this post is that ONE drive is not a good backup... but better than no backup at all. TWO drives with one always offsite means you can survive fire/flood/theft that takes out the Mac(s) at home AND the backup drive at home. Just do it.