I'm used to using Ditto on windows, and need something similar on my mac mini.
If you do not want all the images you copy to sit in clipboard then Clip Menu can be ruled out and Jumpcut works good.
There's a Jumpcut fork - Flycut. I do not see any difference from Jumpcut, except that it(Flycut) seems to be in, relatively more, active development.
I'd recommend Alfred and its Powerpack for clipboard history. Aside from the actual keeping of history, you can save snippets that you use often and call them up with a combination of letters and search among recently copied texts. Alfred's interface for this is much nicer than Jumpcut's in my opinion. I haven't tried any of the others. I haven't found any application to be incompatible with Alfred either.
The price of the Powerpack might seem a little steep for just a clipboard history keeper, but Alfred can do so much more. It has become one of my most essential apps, so give it a try.
Two other clipboard managers that have not been mentioned include:
The simply useful clipboard manager
A clipboard manager with a difference, you can copy and paste between different Macs (and PCs!) over your wired or wireless network! Stuf uses DropBox, so can share your clipboard in the office, or anywhere in the world.
I'm quite attached to ClipMenu.
It's simple, yet powerful enough for all my needs. It even supports snippets which are so useful for a programmer like me.
If you're already using LaunchBar, it has a clipboard manager built in. It's simple, but works just how I would need it to.