Maintaining our Mac

So, I went through the threads for a little while and didn't find a similar question, I apologize in advance if this was recently posted....

I've read many different things, and am curious about the insight you guys have.

In your opinions, what is the best way to maintain your hard drive and ensure optimal performance.
From what I understand, the idea of defragging doesn't really apply to the mac OS....am I wrong on that...Thanks in advance!

Fragmentation does happen on Macs, but Mac OS X does a pretty good job of handling file fragmentation in general. Mac OS X does regular maintenance checks and operations in the background which I believe are weekly and monthly to ensure optimal performance.

If you are anal about these things (I kind of am) you can download the free OnyX to perform cleanup operations manually.

There are also defragment applications but I don't know of any that are updated regularly and free.

Run repair disk permissions after any major application install, before and after any software updates, and otherwise, once a month for good practice.
It is good to leave your mac on overnight once in a while (even though over the 2yrs that I have had this one, I have only turned it of a few times) as it carries out it's own maintenance in the early hours of AM.

Main Menu Is another good little app you can try on trail basis and if you like then buy... As i have BC IMO i think this one is one of the easiest i have used and does a great job .....

Consistently getting back 1-2 Gb every clean which i do fortnighty

Agreed, I use main menu.... but I use the free version 1.7.4 which has served me well too.