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In general you don't need any. It'll look after itself, especially if you leave it on (and no sleeping) overnight every so often.
 
When I first switched to Mac OS X I would run some maintance programs such as onyx, macjaintor et al. however as time went on I saw no advantage to running them. Now I haven't used a single program like that for about 2 years now and have never had any problems from doing so.

Mac OS X does take care of itself very well. If you want to kick OS X to run its own maintenance scripts then paste this into terminal

sudo periodic daily weekly monthly

However as I said it will do it automatically by itself anyway so there really is no need.
 
When I first switched to Mac OS X I would run some maintance programs such as onyx, macjaintor et al. however as time went on I saw no advantage to running them. Now I haven't used a single program like that for about 2 years now and have never had any problems from doing so.

...
My experience is very similar. About four years ago, I had a problem that was fixed by running File System Check (fsck -fy) from the command line in Single User Mode. However, user-initiated routine maintenance in MacOS X is a waste of time. If you use a commercial utility for routine maintenance, then you are also wasting your money.
 
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