OK, I know most people are looking for the biggest and baddest clipboard manager, and I'm no different. But over the years, I've noticed that I have subconsciously settled on the following applications:
Arsclip
Clipboard Help+Spell
So the way I look at it, I don't really need a database manager, notetaker, etc. A lot of the options out there will have some notetaking capabilities within the clipboard manager. Even CHS has this. That's good and all, but it's a separate issue from the clipboard features. So what I'm saying is don't make the mistake of choosing a clipboard software because it has additional notetaking storage/retrieval features that you find useful. I say that because if there are notetaking features that you need, there are tons of better options and alternatives for that.
Anyway, for clipboard specific functions, there's one feature that dominates my usage: the pop-up menu under the mouse pointer. That's one of the most productive features I've ever encountered as far as copy/pasting goes. Wherever you need to paste something, you can hit a hotkey and a menu will popup under the mouse with all the past dozens of clips, and you simply choose the one you'd like to paste. I basically ignore most other features in the clipboard software.
I alternate between which software I like better between ARSclip and CHS. They both do the popup thing well. For the popup, I very slightly prefer Arsclip. But CHS is a better made program overall, I just have a couple of minor quibbles with it. Arsclip's preferences and layout can be a little chaotic, that's why I say that.