I have to disagree about Reddit. Reddit is a huge site, with over 250,000 subreddits. Some parts of it are indeed toxic, /r/politics is a good example of this. But there's tons of subreddits for various obscure things, and they're nice places to talk to like-minded people. For instance, there's a subreddit for my car, and there's no toxicity there, just people asking questions about stuff and exchanging tips ("has anyone else experienced this problem?"). Or there's subreddits where people just post pictures of stuff and comment on them (/r/earthporn is a good example if you like pretty nature photos).
The toxicity comes when you have a forum where there's wildly divergent views, so naturally something like /r/politics is going to be filled with nastiness (and for good reason: people who support that other candidate are idiots!! :-) But in someplace like /r/earthporn, what is there to fight about? "This picture of the Grand Canyon at sunset is gorgeous!" "No it isn't, you're a moron!" Some things just lend themselves to conflict a lot more than other things. It's pretty hard to get into an ideological fight about a nature photo. So if you restrict yourself to those subreddits, you can avoid any toxicity I think.