I know most of blogger are wordpress user, and I know it is good. There are a lot of plug-in which exploited by those wordpress fans, and the function is diverse, so I am not sure which ones are good for my blog, would you want to share?
I use essentials plugins and the most important plugins. I avoid using unneccessary plugins. If you go to wordpress plugins website, you will know which plugins are the most popular, which means those are most downloaded one.
You can't just ask others to share which plugins to use. Each blog is different and require different plugins. I agree with KimiGermany that you should avoid unneccessary plugins. For SEO, I recommend using a wordpress theme that already has SEO options built into it like the thesis theme. However, if you are a beginner at SEO the "All in one SEO" plugin works just fine even though its not the "best" as maxiseo stated. There are far better SEO plugins out there for more experience SEOers. Just take a moment to ask yourself this one question "What do I want to do with my blog?" and find the plugins that will help you do so.
If you can code it do it, plugins are bloated and can slow a site down. I use around 4 or 5 per site I run and the rest I figure out how to add the code in a proper well coded way!
As it turns out, I just created a blog today on this topic. Hope you find it helpful. The feedback on the recommendations so far has been good. 22 Best Must Have WordPress Plugins