Question: I see a lot of blogs that seem to have really cluttered sidebars, with a ton of additional widgets, navigation, etc, that I never find myself using. What are some tips for things that make good additions to the sidebar, and some things that are unnecessary? 

One example that springs to mind are Tag Clouds. I see these everywhere, but how often to people actually use them?

Answer: 
I never use the tags cloud. Vote up if you do not use them as well ;-)
Maybe it's just me, but I *like* when a blog has a tag cloud. It lets me see at a glance what kinds of things the author talks about, and gives me a really easy way to browse the content that I'm interested in. I also like the archive links, if I've just discovered a blog that's been around for a while and I want to go back to the beginning and get caught up.

I agree, though, that a lot of extra widgets in a sidebar make me not want to visit certain sites that I may otherwise frequent. All of those things have to load and initialize, and that takes time and resources I'd rather not spend.