OK OK, so I have a lot of those, lol. Most of them happen to be services, and a few are paid.
When it comes to social media, (besides Steemit, of course!) I like Gab.ai, Micro.blog, and Reddit, for some things, (mostly tech-related.) Of course I use Twitter, (and put up with FB from time-to-time,) but they aren't my favorite things.
If you ask me about RSS, I'd probably mention Simple RSS reader, which is lacking a few features, but it's literally one of the very few RSS readers I can actually use. It doesn't fit all my criteria, I got used to how Google reader list view was designed, (a heading with a headline, an excerpt and a link,) and this doesn't do that. It also lacks a bookmarklet and infinite scroll. I love HNRSS for getting RSS feeds from Hacker News, you can get a feed of posts matching anything you want to search for, plus show and ask HN.
I need a place to put all the links I find while reading RSS and/or social media, right? For that I think Linklocker is epic! Save for later is also good.
When it comes to search engines, I use and love the fabulous DuckDuckGo, but there are many, many others. I think a post on Google search alternatives might be in order.
For goal-setting, I use 43things for short-term goals, and PopClogs for long-term/someday goals. 43T actually shut down back in 2014, and a couple people from the community brought it back. Unfortunately they aren't keeping up with the spam though so it's taking over. PopClogs is cool because it lets you add unlimited goals. My ideal goal-setting site would let you either add unlimited goals and have unlimited lists, (for instance someday, yearly etc,) or have like 50-100 goals in each list.
OK OK so this has gotten to be rather long. Those are just a few of my non-obvious favorites. I intend to write more posts about Google/FB/Twitter alternatives in the future.