Wanted to be on a reasonably big instance, since I figure they’re more likely to stick around in the long run. Lemmy.ml was closed for registration at the time (might still be, idk), and plus I have some disagreements with the admins, so I chose lemmy.world. I’m pretty happy here and don’t see a reason to change personally, although the server’s getting pretty overloaded recently so we’ll see.
I’ve been using this userscript to redirect all links to my instance. If you’ve never installed a userscript, it’s pretty easy, you just need to install the Tampermonkey browser extension (there are others but it’s the one I use), then click the greasyfork link in the post I linked, and click install.