Twitter: The perfect echo-chamber where you follow people you agree with and unfollow and/or block anyone that doesn't share your opinion.
Reddit: Depends on mods - Memo: The best
Best of memo is yet to come. I have it running on my computer. No echo chamber for real. 00EEB0B1720FB2EB5E049C8F8BCF8A195F76FDD5AC0346718ED90BC82354EC7E