- lemm.ee is the second most active instance and avoids joining Lemmy.world which is already too big
- reddthat.com is cool if you don't want downvotes
- sh.itjust.works works, if you don't mind the name
- if you are based in Europe, discuss.tchncs.de is very well managed (they have other services at https://tchncs.de/)
- if you are based in North America, lemmy.ca is nice
That's pretty much it.
For the transfer of communities, there is a tab in the user settings to export your settings (including subscriptions) to a JSON file. You can then import it to your new account.