Actually the problem with Reddit are low-functioning people who join subreddits for the attention and trolling. Most of them a griefers and almost all of them are looking for porn and other stuff like that.

I have a few small subreddits I get on that seem to be free of that:

http://www.reddit.com/r/DiscordianHumanism/

http://www.reddit.com/r/OS2/

http://www.reddit.com/r/artificial/

http://www.reddit.com/r/KindleFreebies/

http://www.reddit.com/r/ebookdeals/

http://www.reddit.com/r/MachineLearning/

http://www.reddit.com/r/retrobattlestations/

You will find better content on those Subreddits even if they don't have a lot of members on them like the others that are so popular that they get the low functioning trolls and attention seekers who cause only trouble.

The DiscordianHumanism subreddit was created because of the trolls on Atheism and SecurlarHumanism and sort of combines Discordianism with Humanism for a different take on the world, etc.

A lot of the subreddits where you ask for advice, you often get bad advice and a groupmind who votes up bad advice and votes down good advice. This is because the low functioning people outnumber the mid-functioning and high-functioning people. You will find a lot of the low-functioning people are under 18, and posting from their parent's basement with no supervision.